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Sample records for adriatic sea mediterranean

  1. Microbial respiration and trophic regimes in the Northern Adriatic Sea (Mediterranean Sea)

    NASA Astrophysics Data System (ADS)

    La Ferla, Rosabruna; Azzaro, Maurizio; Maimone, Giovanna

    2006-08-01

    Remineralization in the Northern Adriatic Sea has been examined by studying the respiratory rates, through electron transport system activity, in four systems identified on the basis of different salinities, caused by riverine outflows, and different productivity regimes measured by apparent oxygen utilization. The sea waters influenced by river discharges were characterized by high respiratory activity while in fully marine waters respiration fell close to the typical value for the surface pelagic Mediterranean waters. A speculative approach to quantify the trophic balance in the examined sub-systems was adopted and the following ratios were computed: Primary Production/Respiration (PP/R); Primary Production/(Bacterial Production + Respiration) [PP/(BP + R)]; (Dissolved Organic Carbon + Particulate Organic Carbon)/Respiration [(DOC + POC)/R], using the data generated at the same time from the same multidisciplinary cruises. High variability of these metabolic ratios in the described subsystems occurred, so that shifting autotrophy and heterotrophy patterns through summer-winter and cross-productivity front trends occurred. Episodic heterotrophy has been found to happen in the North Adriatic Sea, although this is normally considered a productive ecosystem.

  2. Matching oceanography and genetics at the basin scale. Seascape connectivity of the Mediterranean shore crab in the Adriatic Sea.

    PubMed

    Schiavina, M; Marino, I A M; Zane, L; Melià, P

    2014-11-01

    Investigating the interactions between the physical environment and early life history is crucial to understand the mechanisms that shape the genetic structure of marine populations. Here, we assessed the genetic differentiation in a species with larval dispersal, the Mediterranean shore crab (Carcinus aestuarii) in the Adriatic Sea (central Mediterranean), and we investigated the role of oceanic circulation in shaping population structure. To this end, we screened 11 polymorphic microsatellite loci from 431 individuals collected at eight different sites. We found a weak, yet significant, genetic structure into three major clusters: a northern Adriatic group, a central Adriatic group and one group including samples from southern Adriatic and Ionian seas. Genetic analyses were compared, under a seascape genetics approach, with estimates of potential larval connectivity obtained with a coupled physical-biological model that integrates a water circulation model and a description of biological traits affecting dispersal. The cross-validation of the results of the two approaches supported the view that genetic differentiation reflects an oceanographic subdivision of the Adriatic Sea into three subbasins, with circulation patterns allowing the exchange of larvae through permanent connections linking north Adriatic sites and ephemeral connections like those linking the central Adriatic with northern and southern locations. PMID:25294324

  3. The bivalve Glycymeris pilosa as a multidecadal environmental archive for the Adriatic and Mediterranean Seas.

    PubMed

    Peharda, Melita; Black, Bryan A; Purroy, Ariadna; Mihanović, Hrvoje

    2016-08-01

    We evaluated the potential of Glycymeris pilosa as an environmental indicator for the Mediterranean region by applying sclerochronological techniques on a sample set collected from Pašman Channel in the middle Adriatic Sea. Maximal longevity of analyzed shells was 69 years. Growth increments in acetate peels of the hinge region had clear boundaries, and there was a strongly synchronous signal in growth-increment width among individuals. The final, replicated chronology spanned 1969 to 2013. Shell growth negatively correlated with local summer sea temperatures and positively with November precipitation. High correlation between shell growth and circulation patterns in the northern Ionian was also observed, with slower growth occurring during cyclonic regimes. Given its broad distribution in the region and the ability to crossdate, generate annually-resolved chronologies, and of a length that substantially overlaps with observational records, G. pilosa has considerable potential to test hypotheses relating to environmental variability and biological response in the Mediterranean. PMID:27254745

  4. Long-term oceanographic variability of the South Adriatic Gyre (Mediterranean Sea) and a large-scale climate pattern

    NASA Astrophysics Data System (ADS)

    Shabrang, Laleh; Menna, Milena; Pizzi, Cinzia; Lavigne, Heloise; Civitarese, Giuseppe; Gacic, Miroslav

    2015-04-01

    The interannual variability of the South Adriatic Gyre and its relation to the wind vorticity and the large climatic pattern (North Atlantic Oscillation - NAO), has been studied using the time series of satellite altimetry data and ocean surface wind products. The Adriatic Sea is a source of main component of the dense water for the entire Eastern Mediterranean - Eastern Mediterranean) Deep water. The cyclonic circulation observed in the South Adriatic area is mainly sustained by the wind forcing, as suggested by the positive correlation between the rate of change of the current vorticity and the wind stress vorticity. Nevertheless, the influence of vorticity advection from the adjacent area (North Ionian Sea) cannot be ignored and it is more significant during the anticyclonic phase of Adriatic-Ionian Bimodal Oscillation System. The geostrophic current vorticities of the South Adriatic and North Ionian Seas are correlated with a time lag of 15 months, which corresponds to an advection speed of ~1 cm/sec. The different wind configuration, observed during the positive (NAO+) and negative (NAO-) NAO states, induces the stronger vorticity during NAO- and vice versa. Moreover, the positive correlation between the NAO index and the frequency of the cold and dry Northerly wind suggests the strengthening of the winter convection, and of the consecutive deep water formation, during the NAO+ states. Southern Adriatic area, being subject to the winter convection, is characterized by the late winter/early spring algal bloom. Spatially averaged surface chorophyll concentrations were correlated with the northerly wind frequencies and it was shown that the two biological productivity regimes likely exist: the subpolar one and the subtropical one depending on the frequency of windy days. We also show that the bloom timing is a linear function of the wind frequency and it can vary within the range of almost two months.

  5. Spatial and temporal variability of pico-, nano- and microphytoplankton in the offshore waters of the southern Adriatic Sea (Mediterranean Sea)

    NASA Astrophysics Data System (ADS)

    Cerino, F.; Bernardi Aubry, F.; Coppola, J.; La Ferla, R.; Maimone, G.; Socal, G.; Totti, C.

    2012-08-01

    The spatial and temporal variability of phytoplankton were investigated in the southern Adriatic Sea in the period November 2006-June 2008. Three stations were sampled along the Bari-Dubrovnik transect with a seasonal frequency (except summer 2007 and spring 2008) at four depths (surface, maximum fluorescence depth and two intermediate depths), with the aim of analyzing the structure of phytoplankton community and evaluate the standing stocks of the three size fractions (pico-, nano- and microphytoplankton). Abundances were on average 5.41×107±5.97×106 cells l-1 for picophytoplankton, 1.00×106±6.70×104 cells l-1 for nanophytoplankton and 2.16×104±7.46×103 cells l-1 for microphytoplankton. Total biomass ranged from 8.5 to 80.7 μg C l-1. The highest values were recorded in April 2007 (38.4±5.9 μg C l-1), and the lowest ones in February 2008 (13.8±1.5 μg C l-1). Picophytoplankton was generally the most abundant phototrophic fraction (on average, 96% of the total abundances and 49% of the total biomass), while nano- and microphytoplankton provided a minor contribution (4% and less than 1% of total abundance and 35% and 16% of total biomass for nanophytoplankton and microphytoplankton, respectively). A decreasing gradient from west to east was observed for pico- and nanophytoplankton abundances and for total biomass. The low biomass values and the dominance of the autotrophic picoplankton fraction in the whole area reflected a general oligotrophic condition. The easternmost station (AM9), characterized by the lowest phytoplankton abundances and biomass and low nutrient concentrations, resulted in still more oligotrophic condition and probably influenced by the Ionian Surface Water (ISW), coming from the eastern Mediterranean.

  6. Seafloor morphology of the Montenegro/N. Albania Continental Margin (Adriatic Sea-Central Mediterranean)

    NASA Astrophysics Data System (ADS)

    Del Bianco, Fabrizio; Gasperini, Luca; Giglio, Federico; Bortoluzzi, Giovanni; Kljajic, Zoran; Ravaioli, Mariangela

    2014-12-01

    High-resolution multibeam morpho-bathymetric maps and a dense grid of seismic reflection profiles show relict and palimpsest geomorphologic features along the Montenegro/Northern Albanian Continental Margin. This sector of the Eastern Adriatic shelf, at the external front of the Dinarides Chain, is characterized by highly variable seafloor patterns and depositional styles, and shows a peculiar alternation of large-scale troughs and ridges, probably caused by tectonic compressive deformations. These tectonically controlled morphologies are overprinted by the result of sedimentary processes, such as progradation at river outflows, erosion, and reworking of sediments by longshore currents, as well as gravity-driven process caused by sediment loading and seismic shaking. Physiographic domains along this shelf-slope margin include (i) an inner and an outer shelf, separated by two major topographic highs, the Kotor and the Bar ridges; (ii) a drowned lobate delta formed during the last phase of sea level fall, likely fed by the Buna/Bojana drainage basin; and (iii) a continental slope affected by gravity-driven faulting and mass-wasting processes. Seafloor reflectivity maps, ground-truthed by grain-size analysis of bottom sediments, reveal that fine-grained deposits accumulate in the inner shelf, while other sectors appear starved. The effects of the last sea-level rise is testified by the presence of seabed forms diagnostic of erosion or depositional processes, such us large dunes, sediment ridges and sediment waves, which were studied to infer the effect of bottom currents under the present-day oceanographic regime and in the recent past. This paper presents a first description of geomorphologic features observed along the Montenegro/Northern Albanian Continental Margin, in the context of Late Quaternary sea-level changes.

  7. Rospo Mare (Adriatic Sea) - An oil-bearing paleokarst in the Mediterranean region

    SciTech Connect

    Soudet, H.; Sorriaux, P.; Michaud, F. )

    1990-05-01

    The oil-bearing paleokarst at Rospo Mare is located in the Adriatic Sea, 20 km off the Italian coast. The reservoir lies at a depth of 1,300 m and consists of a paleokarst of Oligocene to Miocene age that developed within Cretaceous limestones, now covered by 1,200 m of Miocene-Pliocene clastics. The oil column is about 140 m. The karstic nature of the reservoir was identified through vertical cored drill holes, which allowed us to analyze the various solution features and the sedimentary infill (speleothems, terra rossa, marine clays), as well as their vertical distribution. Observations concerning the upper part of the reservoir were compared to a paleokarst of the same age, outcropping widely onshore, in quarries located nearby. Erosion morphology at the top of the karst is highly irregular, including especially paleovalleys as well as many pit-shaped sink holes. Detailed knowledge of that morphology through geophysics helped optimizing the development of the field through horizontal drilling.

  8. Interannual variability of the Adriatic Sea circulation

    NASA Astrophysics Data System (ADS)

    Beg Paklar, Gordana; Sepic, Jadranka; Grbec, Branka; Dzoic, Tomislav; Kovac, Zarko; Ivatek-Sahdan, Stjepan

    2016-04-01

    The Regional Ocean Modeling System (ROMS) was implemented in order to reproduce interannual variability of the Adriatic Sea circulation. Simulations and model result analysis were performed for a three-year period from 1st January 2011 to 31st December 2013. ROMS model run was forced with realistic atmospheric fields obtained from meteorological model Aladin, climatological river discharges, tides and Mediterranean circulation imposed at the southern open boundary. Atmospheric forcing included momentum, heat and water fluxes calculated interactively from the Aladin surface fields during ROMS model simulations. Model results were compared with available CTD and ADCP measurements and discussed in the light of the climatological circulation and thermohaline properties of the Adriatic Sea and its coastal areas. Interannual variability in the Adriatic circulation is related to the prevailing atmospheric conditions, changes in the hydrological conditions and water mass exchange at the Otranto Strait. Basic features of the Adriatic circulation - basin-wide cyclonic circulation with several embedded smaller cyclonic gyres around main pits - are well reproduced by ROMS model. Modelled temperatures and salinities are within corresponding seasonal intervals, although measured profiles generally indicate stronger stratification than modelled ones. Summer circulation in 2011 with current reversal obtained along the eastern Adriatic coast was related to the sampling results of the early fish stages as well as to ARGO drifter movements. Simulated fields from the Adriatic scale model were used to prescribe the initial and open boundary conditions for the interannual simulation in the middle Adriatic coastal domain.

  9. Microbial pollution indicators and culturable heterotrophic bacteria in a Mediterranean area (Southern Adriatic Sea Italian coasts)

    NASA Astrophysics Data System (ADS)

    Stabili, L.; Cavallo, R. A.

    2011-05-01

    In the present study we evaluated the degree of microbial water pollution along the coast line between Brindisi and Santa Maria di Leuca (Southern Adriatic Sea) as well as the culturable heterotrophic bacteria abundances and biodiversity in relation to the microbiological quality of the water. A total of 3773 colonies were isolated, subcultured and identified by several morphological, cultural and biochemical methods including the standardized API 20 E and API 20 NE tests. Along the examined coastal tract the microbial pollution indicators were always below the tolerance limits for bathing waters defined by the CEE directive, suggesting a good sanitary quality. Concerning culturable heterotrophic bacteria, different temporal density trends were observed in the four sites in relation to their geographical position. A positive relationship between the bacterial abundances and the temperature was observed in S. Cataldo and Otranto. The culturable bacterial community was mainly composed of the genera Aeromonas, Pseudomonas, Photobacterium and Flavobacterium. The Enterobacteriaceae family represented a conspicuous component of the bacterial community too. Bacilli were predominant among the Gram-positive bacteria. Of interest is the isolation of yeasts (2% at the surface and 1% at the bottom) taking into account their capability of biodegradation of various materials. Because of the low level of microbial pollution recorded, our results are indicative of the natural variation and diversity of the culturable bacterial community in such an oligotrophic ecosystem and could represent a good point of comparison with other ecosystems as well as a baseline for long term studies aimed to evaluate the effects of environmental fluctuations and human impacts on this aspect of biodiversity in coastal areas.

  10. Delta growth and river valleys: the influence of climate and sea level changes on the South Adriatic shelf (Mediterranean Sea)

    NASA Astrophysics Data System (ADS)

    Maselli, V.; Trincardi, F.; Asioli, A.; Ceregato, A.; Rizzetto, F.; Taviani, M.

    2014-09-01

    Incised valleys across continental margins represent the response of fluvial systems to changes in their equilibrium dynamics, mainly driven by base level fall forced by glacial-eustatic cycles. The Manfredonia Incised Valley formed during the last glacial sea level lowstand, when most of the southern Adriatic shelf was sub-aerially exposed but the outer shelf remained under water. The pronounced upstream deepening of the valley is ascribed to river incision of the MIS5e highstand coastal prism and related subaqueous clinoform under the influence of MIS5-4 sea level fluctuations, while the downstream shallowing and narrowing mainly reflects the impact of increased rates of sea level fall at the MIS3-2 transition on a flatter mid-outer shelf. Until 15 ka BP, the valley fed an asymmetric delta confined to the mid-outer shelf, testifying that continental and deep marine systems remained disconnected during the lowstand. Sea level rise reached the inner shelf during the Early Holocene, drowning the valley and leading to the formation of a sheltered embayment confined toward the land: at this time part of the incision remained underfilled with a marked bathymetric expression. This mini-basin was rapidly filled by sandy bayhead deltas, prograding from both the northern and southern sides of the valley. In this environment, protected by marine reworking and where sediment dispersal was less effective, the accommodation space was reduced and autogenic processes forced the formation of multiple and coalescing delta lobes. Bayhead delta progradations occurred in few centuries, between 8 and 7.2 ka cal BP, confirming the recent hypothesis that in this area the valley was filled during the formation of sapropel S1. This proximal valley fill, representing the very shallow-water equivalent of the cm-thick sapropel layers accumulated offshore in the deeper southern Adriatic basin, is of key importance in following the signature of the sapropel in a facies-tract ideally from the

  11. A sea of worms: polychaete checklist of the Adriatic Sea.

    PubMed

    Mikac, Barbara

    2015-01-01

    The checklist of polychaetes of the Adriatic Sea (Mediterranean) based on bibliographic sources published from 1840 to 2014, as well as on novel data, with 49 new records for the area, is herein presented. The Adriatic Sea polychaete fauna comprises at present of 764 species in 360 genera and 62 families. The richest family is the Syllidae, with 112 species (c.a. 15% of the all taxa). Eight families account for as much as 50% of the diversity (Syllidae, Serpulidae, Sabellidae, Phyllodocidae, Spionidae, Polynoidae, Terebellidae and Nereididae). Among the three Adriatic sectors (Northern, Central and Southern Adriatic), the Northern Adriatic is the richest one, whereas the composition of the most diverse families is very similar in all sectors. Data on endemisms (6), aliens (29) and valid species with the type locality in the Adriatic Sea (90) are also discussed. The list of all relevant papers citing each species in the Adriatic is included, allowing future detailed information retrievals for distinct purposes. Results suggest that the number of species will keep increasing in the future, as new surveys will be undertaken, so regular updates of the present list will be necessary. PMID:25947537

  12. Fishing management scenarios to rebuild exploited resources and ecosystems of the Northern-Central Adriatic (Mediterranean Sea)

    NASA Astrophysics Data System (ADS)

    Fouzai, Nadia; Coll, Marta; Palomera, Isabel; Santojanni, Alberto; Arneri, Enrico; Christensen, Villy

    2012-10-01

    We examined various fishing management options to recover exploited marine resources and ecosystems of the Northern-Central Adriatic Sea. Dynamic simulations were based on a spatial ecological model previously calibrated with time series of data. Scenarios regarding spatial management were evaluated with the establishment of two marine protected areas, respectively, in the Pomo pit and the northern region. In addition, three temporal simulations of temporary closures and overall reduction of fishing effort of demersal and pelagic fleets (bottom, mid-water trawls and purse seines) were also considered. Simulations were run for 45 years (1975-2020), including the calibration period (1975-2002), and changes in biomass and catch of marine resources were analyzed. Our results confirm that current fishing management in the Adriatic Sea does not have clear beneficial impacts for the recovery of exploited resources, which will remain depleted in 2020 if "business as usual" continues. Simulations of alternative management suggest that both protected areas could be beneficial for fish population recovery predicting an increase in the biomass of commercial fish and predatory organisms. Simulations of temporary closures and overall reduction of fishing effort also show significant benefits for several commercial resources. We argue that both management measures may be effective tools to recover exploited ecosystems of the Northern-Central Adriatic Sea and halt the decline of marine resources.

  13. Levels of organochlorine compounds in the Mediterranean blue mussel from the Adriatic Sea.

    PubMed

    Kozul, Darija; Romanić, Snjezana Herceg; Kljaković-Gaspić, Zorana; Veza, Jere

    2009-12-01

    The distribution of polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) was investigated in Mediterranean blue mussel collected at four locations in Mali Ston Bay few times a year in 2005–2007. OCPs were found in all samples and levels ranged between 0.07 and 7.58 ng g−1 dry wt. Levels of PCBs ranged between 0 (below detection limit) and 21.55 ng g−1 dry wt. For most analyzed compounds there were no significant level changes between the 3 years. Exceptions are decreased levels of β-HCH, DDD, and PCB-138 and increased levels of γ-HCH and DDT in 2007. However, mussels from this area are applicable for human diet. PMID:19626261

  14. Evidence of butyltin biomagnification along the Northern Adriatic food-web (Mediterranean Sea) elucidated by stable isotope ratios.

    PubMed

    Fortibuoni, Tomaso; Noventa, Seta; Rampazzo, Federico; Gion, Claudia; Formalewicz, Malgorzata; Berto, Daniela; Raicevich, Saša

    2013-04-01

    The biomagnification of tributyltin (TBT), dibutyltin (DBT), monobutyltin (MBT), and total butyltins (ΣBT) was analyzed in the Northern Adriatic food-web (Mediterranean) considering trophodynamic interactions among species and carbon sources in the food-web. Although it is acknowledged that these contaminants bioaccumulate in marine organisms, it is still controversial whether they biomagnify along food-webs. A wide range of species was considered, from plankton feeders to top predators, whose trophic level (TL) was assessed measuring the biological enrichment of nitrogen stable isotopes (δ(15)N). Carbon isotopic signature (δ(13)C) was used to trace carbon sources in the food-web (terrestrial vs marine). At least one butyltin species was detected in the majority of samples, and TBT was the predominant contaminant. A significant positive relationship was found between TL and butyltin concentrations, implying food-web biomagnification. Coherently, the Trophic Magnification Factor resulted higher than 1, ranging between 3.88 for ΣBT and 4.62 for DBT. A negative but not significant correlation was instead found between δ(13)C and butyltin concentrations, indicating a slight decreasing gradient of contaminants concentrations in species according to the coastal influence as carbon source in their diet. However, trophodynamic mechanisms are likely more important factors in determining butyltin distribution in the Northern Adriatic food-web. PMID:23465397

  15. Two-year study of lipophilic marine toxin profile in mussels of the North-central Adriatic Sea: First report of azaspiracids in Mediterranean seafood.

    PubMed

    Bacchiocchi, Simone; Siracusa, Melania; Ruzzi, Angela; Gorbi, Stefania; Ercolessi, Manuela; Cosentino, Maria Anna; Ammazzalorso, Patrizia; Orletti, Roberta

    2015-12-15

    Since the late 1980s, the North-central Adriatic Sea has frequently experienced blooms of harmful algal species, producing marine lipophilic toxins (MLTs) which accumulate in mussels and pose a serious threat to consumer health. Here, we present a 2-year LC-MS/MS study (2012-2014) of the MLT profile in mussels from the North-central Adriatic Sea in the context of the presence of toxic phytoplankton concentrations in seawater. Okadaic acid increased in mussels from all areas during the summer and autumn-winter periods with a rising trend between 2012 and 2014. In the same periods, Dinophysis sp. increased in abundance in seawater, but the highest densities of algae did not always coincide with the highest levels of toxins in mussels. Yessotoxins (YTXs) content in mussel increased sharply in the autumn-winter periods even exceeding the legal limit; although this accumulation did not always correlated with the YTX-producers in water (such as Lingulodinium polyedrum and Protoceratium reticulatum) a massive bloom of Gonyaulax spinifera was reported in November 2013, suggesting the role of this species in YTXs shellfish contamination. Traces of Azaspiracid 2 (AZA-2) were observed often in mussels during the study period, confirming for the first time the presence of this biotoxin in Mediterranean seafood. PMID:26455996

  16. Eastern-Mediterranean ventilation variability during sapropel S1 formation, evaluated at two sites influenced by deep-water formation from Adriatic and Aegean Seas

    NASA Astrophysics Data System (ADS)

    Filippidi, A.; Triantaphyllou, M. V.; De Lange, G. J.

    2016-07-01

    Present-day bottom-water ventilation in the Eastern Mediterranean basin occurs through deep-water convection originating from the two marginal basins, i.e. Adriatic and Aegean Seas. In the paleo record, long periods of enhanced deep-water formation have been alternating with shorter periods of reduced deep-water formation. The latter is related mainly to low-latitude humid climate conditions and the enhanced deposition and preservation of organic-rich sediment units (sapropels). This study focuses on sedimentary archives of the most-recent sapropel S1, retrieved from two sites under the direct influence of the two deep-water formation areas. Restricted oxygen conditions have developed rapidly at the beginning of S1 deposition in the Adriatic site, but bottom-water conditions have not persistently remained anoxic during the full interval of sapropel deposition. In fact, the variability in intensity and persistence of sedimentary redox conditions at the two deep-water formation sites is shown to be related to brief episodes of climate cooling. In the Adriatic site, sapropel deposition appears to have been interrupted twice. The 8.2 ka event, only recovered at the Adria site, is characterized by gradually increasing suboxic to possibly intermittently oxic conditions and decreasing Corg fluxes, followed by an abrupt re-establishment of anoxic conditions. Another important event that disrupted sapropel S1 formation, has taken place at ca. 7.4 cal ka BP. The latter event has been recovered at both sites. In the Adriatic site it is followed by a period of sedimentary conditions that gradually change from suboxic to more permanently oxic, as deduced from the Mn/Al pattern. Using the same proxy for suboxic/oxic sedimentary redox conditions, we observe that conditions in the Aegean Sea site shift to more permanently oxic from the 7.4 ka event onwards. However, at both sites the accumulation and preservation of enhanced amounts of organic matter have continued under these

  17. Bacterial community shift is induced by dynamic environmental parameters in a changing coastal ecosystem (northern Adriatic, northeastern Mediterranean Sea)--a 2-year time-series study.

    PubMed

    Tinta, T; Vojvoda, J; Mozetič, P; Talaber, I; Vodopivec, M; Malfatti, F; Turk, V

    2015-10-01

    The potential link between the microbial dynamics and the environmental parameters was investigated in a semi-enclosed and highly dynamic coastal system (Gulf of Trieste, northern Adriatic Sea, NE Mediterranean Sea). Our comprehensive 2-year time-series study showed that despite the shallowness of this area, there was a significant difference between the surface and the bottom bacterial community structure. The bottom bacterial community was more diverse than the surface one and influenced by sediment re-suspension. The surface seawater temperature had a profound effect on bacterial productivity, while the bacterial community structure was more affected by freshwater-borne nutrients and phytoplankton blooms. Phytoplankton blooms caused an increase of Gammaproteobacteria (Alteromonadaceae, SAR86 and Vibrionaceae) and shift in dominance from SAR11 to Rhodobacteraceae taxon at the surface. Our results propose the importance of the water mass movements as drivers of freshwater-borne nutrients and of allochthonous microbial taxa. This study emphasizes the prediction power based on association networks analyses that are fed with long-term measurements of microbial and environmental parameters. These interaction maps offer valuable insights into the response of marine ecosystem to climate- and anthropogenic-driven stressors. PMID:24903068

  18. Mercury speciation in the Adriatic Sea.

    PubMed

    Kotnik, Jože; Horvat, Milena; Ogrinc, Nives; Fajon, Vesna; Žagar, Dušan; Cossa, Daniel; Sprovieri, Francesca; Pirrone, Nicola

    2015-07-15

    Mercury and its speciation were studied in surface and deep waters of the Adriatic Sea. Several mercury species (i.e. DGM – dissolved gaseous Hg, RHg – reactive Hg, THg – total Hg, MeHg – monomethyl Hg and DMeHg – dimethylmercury) together with other water parameters were measured in coastal and open sea deep water profiles. THg concentrations in the water column, as well as in sediments and pore waters, were the highest in the northern, most polluted part of the Adriatic Sea as the consequence of Hg mining in Idrija and the heavy industry of northern Italy. Certain profiles in the South Adriatic Pit exhibit an increase of DGM just over the bottom due to its diffusion from sediment as a consequence of microbial and/or tectonic activity. Furthermore, a Hg mass balance for the Adriatic Sea was calculated based on measurements and literature data. PMID:26013591

  19. Prokaryotic dynamics and heterotrophic metabolism in a deep convection site of Eastern Mediterranean Sea (the Southern Adriatic Pit)

    NASA Astrophysics Data System (ADS)

    Azzaro, M.; La Ferla, R.; Maimone, G.; Monticelli, L. S.; Zaccone, R.; Civitarese, G.

    2012-08-01

    We report on investigations of prokaryotic abundance, biomass, extracellular enzymatic activity, prokaryotic heterotrophic production and respiration in the full water column (˜1200 m) of a deep convection site (the Southern Adriatic Pit), carried out on six cruises in 2006-2008. Prokaryotic abundance (PA) varied vertically and temporally and ranged from 1.2 to 20.4×105 cell ml-1. Cell volumes, generally increased with depth; the lowest mean cell volume was observed in a period with no active convective process (Feb-07) and the highest in a period of stratification (Jun-08) following the convection process occurred in Feb-08. Prokaryotic biomass decreased with the depth and was related with both seasonal cycles of organic matter and hydrological processes. The picophytoplankton ranged in the upper layer (UL) from 0.089 to 10.71×104 cell ml-1. Cells were also recorded till 500 m depth in Feb-08 and this finding could be linked to water convection occurred in the Southern Adriatic Pit in that month. In UL the variations of enzymatic activities as well as leucine-aminopeptidase/ß-glucosidase ratio showed a seasonal trend probably linked to the productive processes of the photic layer. An inverse relation between alkaline phosphatase activity (APA) and phosphate concentrations was found (APA=0.0003PO4-1.7714, R2=0.333, P<0.05). Generally cell-specific enzymatic activities increased with depth as did cell-specific carbon dioxide production rates, while cell-specific prokaryotic heterotrophic production had an opposite trend. High values of prokaryotic growth efficiency registered in the deep layers in Nov-06 reflected a supply of preformed C transported within the deep water masses. Overall, in 2007 when no convective phenomenon was observed, the variability of prokaryotic metabolism was governed by the seasonal cycle of the organic matter, while in Nov-06 and Jun-08 the dynamics of deep water ventilation influenced the trend along the water column of many microbial

  20. box modeling of the eastern mediterranean sea

    NASA Astrophysics Data System (ADS)

    Ashkenazy, Y.; Stone, P. H.

    2003-04-01

    Recently (~1990) a new source of deep water formation in the Eastern Mediterranean was found in the southern part of the Aegean sea. Till then, the only source of deep water formation in the Eastern Mediterranean was in the Adriatic sea; the rate of the deep water formation of the new Aegean source is 1Sv=10^6m^3/s, three times larger then the Adriatic source. We develop a simple 3 box-model to study the stability of the thermohaline circulation of the Eastern Mediterranean sea. The 3 boxes represent the Adriatic sea, Aegean sea, and the Ionian sea. The boxes exchange heat and salinity and may be described by a set of nonlinear differential equations. We analytically analyze these equations and find that the system may have one, two, or four stable flux states. We consider two cases for which the temperatures of the boxes are (i) fixed or (ii) variable. After setting the parameters to correspond to the Eastern Mediterranean we find that the system has two stable states, one with (i) two thermally dominant sources of deep water formation in the Adriatic and Aegean and the other with (ii) a salinity dominant source of deep water formation in the Adriatic and a thermally dominant source in the Aegean. While the Adriatic thermally dominant source is comparable to the observed flux of 0.3Sv the Aegean source has much smaller flux than the observed value. This situation is analogous to the state of the thermohaline circulation pre 1990 where the only source of deep water formation was in the Adriatic. If we decrease the atmospheric temperature of the Aegean box by 2C in accordance with recent observations, we find that the deep water formation of the Aegean increases significantly to a value comparable to the recently observed flux.

  1. Changes in the Adriatic oceanographic properties induced by the Eastern Mediterranean Transient

    NASA Astrophysics Data System (ADS)

    Vilibić, I.; Matijević, S.; Šepić, J.; Kušpilić, G.

    2012-06-01

    Long-term time series of physical and chemical parameters collected between 1960 and 2010 along the Palagruža Sill transect, Middle Adriatic Sea, have been investigated in terms of average water properties and their variability. Nutrients, especially orthophosphates, reached rather high levels of concentration below the euphotic zone between 1991 and 1998, the highest levels in the investigated period. Simultaneously, the N:P ratio, which is normally higher than 25:1, decreased to values less than 16:1 in the euphotic zone, indicating a switch from typical phosphorus to nitrogen- limited preconditioning for the primary production. Higher-than-usual nutrient levels peaking in the mid-1990s, coupled with lower-than-usual temperature, salinity, dissolved oxygen and pH values, are presumably related to the flow of the nutrient richer Western Mediterranean waters to the Adriatic below the euphotic layer. These waters, which keep their footprint in the N:P ratio, enter the Adriatic during the anticyclonic phase of the Bimodal Adriatic-Ionian Oscillation (BiOS), which has been uniquely strengthened by the Eastern Mediterranean Transient occurring in the early 1990s. This hypothesis should be confirmed through targeted research and modelling exercises, as it is highly relevant for the biogeochemistry of the Adriatic Sea.

  2. Links between Sea Level in the northern Adriatic sea and large scale patterns

    NASA Astrophysics Data System (ADS)

    Scarascia, L.; Lionello, P.

    2012-04-01

    The study analyzes the link between Northern Adriatic sea level (SL) and three variables: sea level pressure over European and North-Atlantic area (SLP), Mediterranean sea surface temperature (SST) and Mediterranean sea surface salinity (SSS). Sea level data are provided by monthly values recorded at 7 tide gauges stations distributed along the north-Italian and Croatian coasts (available at the PSMSL Permanent Service of Mean Sea Level). SLP data are provided by the EMULATE data set. Mediterranean SST and SSS data are extracted from the MEDATLAS/2002 database. The study shows that annual sea level variations at Northern Adriatic stations are very coherent so that the northern Adriatic sea level can be reconstructed since 1905 on the basis of only two stations: Venice and Trieste, whose data cover almost the entire 20th century (whereas Croatian data cover only the second half of the century). The inverse barometric, thermosteric and halosteric effects provide the physical basis for a local relation of SL with SLP, SST, SSS implying, if other effects are absent, a sea level increase for increasing temperature and decreasing atmospheric pressure and salinity. However, the statistical model used to quantify the link between SL and these three forcings shows that they have produced no important trend and they cannot explain the observed trend of Northern Adriatic Sea level during the second half of the 20th century. The observed trend can therefore be interpreted as the superposition of land movement and a remote cause. Using SLP, SST and SSS from climate model simulations, no trend is obtained during the 20th century, as well. The same model simulations, considering their continuations for the 21st century show that local effects (mainly warming of water masses) are likely to produce an increase of about 10cm (with a large uncertainty) at the end of the century. The global signal and the regional land movements have to be added to this result to obtain the actual

  3. Box modeling of the Eastern Mediterranean sea

    NASA Astrophysics Data System (ADS)

    Ashkenazy, Yosef; Stone, Peter H.; Malanotte-Rizzoli, Paola

    2012-02-01

    In ˜1990 a new source of deep water formation in the Eastern Mediterranean was found in the southern part of the Aegean sea. Till then, the only source of deep water formation in the Eastern Mediterranean was in the Adriatic sea; the rate of the deep water formation of the new Aegean source is 1 Sv, three times larger than the Adriatic source. We develop a simple three-box model to study the stability of the thermohaline circulation of the Eastern Mediterranean sea. The three boxes represent the Adriatic sea, Aegean sea, and the Ionian seas. The boxes exchange heat and salinity and may be described by a set of nonlinear differential equations. We analyze these equations and find that the system may have one, two, or four stable flux states. We conjecture that the change in the deep water formation in the Eastern Mediterranean sea is attributed to a switch between the different states on the thermohaline circulation; this switch may result from decreased temperature and/or increased salinity over the Aegean sea.

  4. Sediment dispersal in the northwestern Adriatic Sea

    USGS Publications Warehouse

    Harris, C.K.; Sherwood, C.R.; Signell, R.P.; Bever, A.J.; Warner, J.C.

    2008-01-01

    Sediment dispersal in the Adriatic Sea was evaluated using coupled three-dimensional circulation and sediment transport models, representing conditions from autumn 2002 through spring 2003. The calculations accounted for fluvial sources, resuspension by waves and currents, and suspended transport. Sediment fluxes peaked during southwestward Bora wind conditions that produced energetic waves and strengthened the Western Adriatic Coastal Current. Transport along the western Adriatic continental shelf was nearly always to the south, except during brief periods when northward Sirocco winds reduced the coastal current. Much of the modeled fluvial sediment deposition was near river mouths, such as the Po subaqueous delta. Nearly all Po sediment remained in the northern Adriatic. Material from rivers that drain the Apennine Mountains traveled farther before deposition than Po sediment, because it was modeled with a lower settling velocity. Fluvial sediment delivered to areas with high average bed shear stress was more highly dispersed than material delivered to more quiescent areas. Modeled depositional patterns were similar to observed patterns that have developed over longer timescales. Specifically, modeled Po sediment accumulation was thickest near the river mouth with a very thin deposit extending to the northeast, consistent with patterns of modern sediment texture in the northern Adriatic. Sediment resuspended from the bed and delivered by Apennine Rivers was preferentially deposited on the northern side of the Gargano Peninsula, in the location of thick Holocene accumulation. Deposition here was highest during Bora winds when convergences in current velocities and off-shelf flux enhanced delivery of material to the midshelf. Copyright 2008 by the American Geophysical Union.

  5. Qualified temperature, salinity and dissolved oxygen climatologies in a changing Adriatic Sea

    NASA Astrophysics Data System (ADS)

    Lipizer, M.; Partescano, E.; Rabitti, A.; Giorgetti, A.; Crise, A.

    2014-10-01

    An updated climatology, based on a comprehensive data set (1911-2009) of temperature, salinity and dissolved oxygen, has been produced for the whole Adriatic Sea with the variational inverse method using the DIVA (Data-Interpolating Variational Analysis) software. Climatological maps were produced at 26 levels and validated with ordinary cross-validation and with a real vs. synthetic temperature-salinity diagram intercomparison. The concept of climatology-observation misfit (COM) has been introduced as an estimate of the physical variability associated with the climatological structures. In order to verify the temporal stability of the climatology, long-term variability has been investigated in the Middle Adriatic and the South Adriatic pits, regarded as the most suitable records of possible long-term changes. Compared with previous climatologies, this study allows a clear identification of the seasonal dynamic of the southern Adriatic, where a clear oxygen minimum is typically observed in the centre of the South Adriatic Gyre. New and better resolved features emerged from this analysis: (1) below 100 m all properties profoundly differ between the central and the southern Adriatic and seem characterized by different biogeochemical dynamics; (2) the South Adriatic Pit clearly shows the remote effects of the Eastern Mediterranean Transient, while no effect is observed in the Middle Adriatic Pit; (3) the deepest part of the southern Adriatic seems now to be significantly saltier (+0.18 psu since the period 1910-1914, with an increase of +0.018 decade-1 since the late 1940s) and warmer (+0.54 °C since 1910-1914) even though a long-term temperature trend could not be statistically demonstrated; (4) the Middle Adriatic Pit shows a long-term increase in apparent oxygen utilization (+0.77 mL L-1 since 1910-1914, with a constant increase of +0.2 mL L-1 decade-1 after the 1970s).

  6. Qualified temperature, salinity and dissolved oxygen climatologies in a changing Adriatic Sea

    NASA Astrophysics Data System (ADS)

    Lipizer, M.; Partescano, E.; Rabitti, A.; Giorgetti, A.; Crise, A.

    2014-02-01

    An updated climatology, based on a comprehensive dataset (1911-2009) of temperature, salinity and dissolved oxygen, has been produced for the whole Adriatic Sea with the Variational Inverse Method using the DIVA software. Climatological maps were produced at 26 levels and validated with Ordinary Cross Validation and with real vs. synthetic Temperature-Salinity diagram intercomparison. The concept of Climatology-Observation Misfit (COM) has been introduced as an estimate of the physical variability associated with the climatological structures. In order to verify the temporal stability of the climatology, long-term variability has been investigated in the Mid Adriatic and the South Adriatic Pits, regarded as the most suitable records of possible long-term changes. Compared with previous climatologies, this study reveals a surface temperature rise (up to 2 °C), a clear deep dissolved oxygen minimum in the South Adriatic Gyre and a bottom summer oxygen minimum in the North Adriatic. Below 100 m all properties profoundly differ between the Middle and the South Adriatic. The South Adriatic Pit clearly shows the remote effects of the Eastern Mediterranean Transient, while no effect is observed in Middle Adriatic Pits. The deepest part of the South Adriatic seems now to be significantly saltier (+0.18 since the period 1911-1914, with an increase of +0.018 decade-1 since the late 1940s) and warmer (+0.54 °C since 1911-1914), even though a long-term temperature trend could not be statistically demonstrated. Conversely, the Middle Adriatic Pits present a long-term increase in apparent oxygen utilisation (+0.77 mL L-1 since 1911-1914, with a constant increase of +0.2 mL L-1 decade-1 after the 1970s).

  7. Long-term climate variability of the Adriatic Sea thermohaline properties using an ensemble of regional ocean hindcast simulations

    NASA Astrophysics Data System (ADS)

    Dunic, Natalija; Vilibic, Ivica; Sepic, Jadranka; Sevault, Florence; Somot, Samuel; Waldman, Robin; Jorda, Gabriel

    2016-04-01

    The Adriatic Sea has a substantial impact on dynamical properties and thermohaline circulation of the Eastern Mediterranean, through a large freshwater input and dense water formation processes that drive the thermohaline circulation of the Adriatic-Ionian basin. Together with Bimodal Adriatic-Ionian Oscillation (BiOS), it represents the major driving process of interannual and decadal variations in thermohaline properties of the Adriatic Sea and Central/Eastern Mediterranean. Recent findings, extracted from the long-term observations, implicate a change in driving Adriatic climate processes, which might be important for future climate of the whole Eastern Mediterranean. The reproduction of these processes may be challenging for climate models, as occurring over limited areas and over daily timescales at the most. For that reason, an ensemble of NEMOMED regional ocean hindcast simulations with different spatial (10 and 6 km) and vertical (43 and 75 z-levels) resolutions, atmosphere (50 and 12 km resolution) and freshwater (from 8 to 43 river mouths in the basin) forcing have been analyzed, focusing on their representativeness for the Adriatic Sea dynamics. Furthermore, new Adriatic river climatology, developed recently within short-term oceanographic studies, has been imposed to the hindcast simulations with an aim to lower model biases. Half-centurial time series of temperature and salinity collected at the Palagruža Sill transect, and at the Jabuka and South Adriatic Pits known to be collectors of the Adriatic dense waters, were used for verification of models. The analyses focused on the reproduction of the Adriatic interannual and decadal variations, including their governing processes, dense water formation and BiOS for the 1980-2012 time period. Once becoming reliably reproduced, it will allow for an assessment of their importance and changes in future climate.

  8. Climatology of temperature, salinity and dissolved oxygen in a changing Adriatic Sea

    NASA Astrophysics Data System (ADS)

    Lipizer, Marina; Crise, Alessandro; Partescano, Elena; Rabitti, Anna; Giorgetti, Alessandra

    2015-04-01

    A new climatology, based on a comprehensive dataset (1911-2009) of temperature, salinity and dissolved oxygen, is presented for the whole Adriatic Sea, by using Data-Interpolating Variational Analysis (DIVA). Climatological maps were produced at 26 levels and validated with Ordinary Cross Validation. The approximation error and the uncertainty degree associated to the updated climatology have been estimated in order to provide information on the reliability of the products obtained. The concept of Climatology-Observation Misfit (COM) has been introduced as an estimate of the uncertainty of the patterns revealed in the climatology, which is induced by the dynamical variability associated with the climatological structures. The uncertainty associated with the climatology, higher in the upper layer and in the northern and shallower part of the basin, underlines the importance of mesoscale processes in the Adriatic Sea. Lastly, in order to identify possible temporal trends, long-term variability has been investigated in the Mid Adriatic and the South Adriatic Pits. New or better resolved features emerged from this analysis: (1) below 100 m all properties profoundly differ between the Middle and the South Adriatic and seem characterized by different biogeochemical dynamics; (2) the South Adriatic Pit clearly shows the remote effects of the Eastern Mediterranean Transient, while no effect is observed in Middle Adriatic Pits; (3) the deepest part of the South Adriatic seems now to be significantly saltier (+0.18 since the period 1910-1914, with an increase of +0.018 decade-1 since the late 1940s) and warmer (+0.54°C since 1910-1914),; (4) the Middle Adriatic Pits present a long-term increase in Apparent Oxygen Utilisation (+0.77 ml l-1 since 1910-1914, with a constant increase of +0.2 ml l-1 decade-1 after the 1970s).

  9. Analysis of mercury and methylmercury concentrations, and selenium:mercury molar ratios for a toxicological assessment of sperm whales (Physeter macrocephalus) in the most recent stranding event along the Adriatic coast (Southern Italy, Mediterranean Sea).

    PubMed

    Squadrone, S; Chiaravalle, E; Gavinelli, S; Monaco, G; Rizzi, M; Abete, M C

    2015-11-01

    Mass stranding of sperm whales (Physeter macrocephalus) is a rare event in the Mediterranean Sea. In September 2014, a pod of seven sperm whales became stranded along the Adriatic coast of Southern Italy. This is the seventh occurrence of this type since 1555 in this sea basin. Total concentrations of mercury (T-Hg), methylmercury (MeHg) and selenium (Se) were measured from brain, muscle, liver and kidney of three female sperm whales, which died in this event. Analyses showed considerable, age-dependent variations in Hg and Se concentrations in the different organs. The contamination levels of T-Hg in the liver (up to 200 mg kg(-1)) and brain (up to 21 mg kg(-1)) samples were markedly higher than those in the kidney and muscle samples. The liver and brain also showed the highest Se levels. Se:Hg molar ratios ⩾1 were observed in all the organs of the three sperm whales, suggesting that Se could protect the animals from Hg toxicity. The risk of Hg-associated neurotoxicity was assessed by comparing our values to thresholds set for neurotoxicity in mammals, and the role of Se in the detoxification process of T-Hg/MeHg is discussed herein. PMID:26233668

  10. 3D seismic geomorphology of mass transport complexes in a foredeep basin: Examples from the Pleistocene of the Central Adriatic Basin (Mediterranean Sea)

    NASA Astrophysics Data System (ADS)

    Dalla Valle, Giacomo; Gamberi, Fabiano; Rocchini, Patrizia; Minisini, Daniel; Errera, Alessia; Baglioni, Luca; Trincardi, Fabio

    2013-08-01

    Three-dimensional (3D) seismic-reflection data has shed light on the character of a series of mass transport complexes (MTCs) emplaced during the Pleistocene in the Pescara Basin (Central Adriatic Sea, Italy). The Pescara Basin is the Plio-Pleistocene inner foredeep of the Central Apennines orogen, which was filled by a rapidly prograding, margin-scale clinoforms system. Three MTCs punctuate the normal turbiditic and hemipelagic sedimentary succession of the Pescara Basin foredeep. MTC_0 is the oldest one and covers an area of around 74 km2. It is composed of three different mass transport deposits (MTDs) resulting from individual collapses that involved a shelf-edge delta during a period of relative sea level rise. MTC_1, the intermediate age MTC, is the largest one, with an area of 90 km2. It has a 10 km wide cookie-bite headwall region that indents the upper slope and, in places, reaches the continental shelf-break. MTC_1 is made up of four laterally and vertically stacked MTDs which are the result of a composite set of failures that migrated progressively upslope in a sedimentary setting dominated by contourite deposits. MTC_2 is the youngest and the smallest one, with an area of 55 km2. It has a 5 km long headwall confined in correspondence with a sedimentary bulge developed in the upper slope. Its geomorphic setting leads us to consider two different episodes of failure rooted at different depths. The investigation of the MTCs, through the coupling of 3D seismic geomorphology, seismic facies analysis and rollover trajectory analysis, reveals that the type of sedimentary environment, the rate of sediment accumulation, the source region and the depth of rooting of the failure, are the major controlling factors on MTC evolution and emplacement. Each MTC of the Pescara Basin foredeep is generally confined within a discrete clinotheme. Finally, the rollover trajectory analysis has shown that, in the PB foredeep, a sediment failure can possibly occur at any

  11. Characterization of aerosols above the Northern Adriatic Sea: Case studies of offshore and onshore wind conditions

    NASA Astrophysics Data System (ADS)

    Piazzola, J.; Mihalopoulos, N.; Canepa, E.; Tedeschi, G.; Prati, P.; Zarmpas, P.; Bastianini, M.; Missamou, T.; Cavaleri, L.

    2016-05-01

    Aerosol particles in coastal areas result from a complex mixing between sea spray aerosols locally generated at the sea surface by the wind-waves interaction processes and a continental component resulting from natural and/or anthropogenic sources. This paper presents a physical and chemical analysis of the aerosol data acquired from May to September 2014 in the Adriatic Sea. Aerosol distributions were measured on the Acqua Alta platform located 15 km off the coast of Venice using two Particle Measuring System probes and a chemical characterization was made using an Ion Chromatography analysis (IC). Our aim is to study both the sea-spray contribution and the anthropogenic influence in the coastal aerosol of this Mediterranean region. To this end, we focus on a comparison between the present data and the aerosol size distributions measured south of the French Mediterranean coast. For air masses of marine origin transported by southern winds on the French coast and by the Sirocco in the Adriatic, we note a good agreement between the concentrations of super-micrometer aerosols measured in the two locations. This indicates a similar sea surface production of sea-spray aerosols formed by bubble bursting processes in the two locations. In contrast, the results show larger concentrations of submicron particles in the North-Western Mediterranean compared to the Adriatic, which result probably from a larger anthropogenic background for marine conditions. In contrast, for a coastal influence, the chemical analysis presented in the present paper seems to indicate a larger importance of the anthropogenic impact in the Northern Adriatic compared to the North-Western Mediterranean.

  12. Characterization of aerosols above the Northern Adriatic Sea: Case studies of offshore and onshore wind conditions

    NASA Astrophysics Data System (ADS)

    Piazzola, J.; Mihalopoulos, N.; Canepa, E.; Tedeschi, G.; Prati, P.; Zarmpas, P.; Bastianini, M.; Missamou, T.; Cavaleri, L.

    2016-05-01

    Aerosol particles in coastal areas result from a complex mixing between sea spray aerosols locally generated at the sea surface by the wind-waves interaction processes and a continental component resulting from natural and/or anthropogenic sources. This paper presents a physical and chemical analysis of the aerosol data acquired from May to September 2014 in the Adriatic Sea. Aerosol distributions were measured on the Acqua Alta platform located 15 km off the coast of Venice using two Particle Measuring System probes and a chemical characterization was made using an Ion Chromatography analysis (IC). Our aim is to study both the sea-spray contribution and the anthropogenic influence in the coastal aerosol of this Mediterranean region. To this end, we focus on a comparison between the present data and the aerosol size distributions measured south of the French Mediterranean coast. For air masses of marine origin transported by southern winds on the French coast and by the Sirocco in the Adriatic, we note a good agreement between the concentrations of super-micrometer aerosols measured in the two locations. This indicates a similar sea surface production of sea-spray aerosols formed by bubble bursting processes in the two locations. In contrast, the results show larger concentrations of submicron particles in the North-Western Mediterranean compared to the Adriatic, which result probably from a larger anthropogenic background for marine conditions. In contrast, for a coastal influence, the chemical analysis presented in the present paper seems to indicate a larger importance of the anthropogenic impact in the Northern Adriatic compared to the North-Western Mediterranean.

  13. Distribution of phosphorus in the eastern Adriatic Sea sediments (Croatia)

    NASA Astrophysics Data System (ADS)

    Matijević, Slavica; Bogner, Danijela; Kušpilić, Grozdan; Veža, Jere

    2014-05-01

    Phosphorus (P) is very important nutrient for the eastern Adriatic Sea owing to its limiting role in the primary production. Orthophosphate concentrations are low (median HPO42- value: 0.039 µmol dm-3) as a consequence of relatively small number of freshwater inflows and cyclonic circulation of oligotrophic eastern Mediterranean water masses. Due to anthropogenic influence in coastal areas such as bays, estuaries and channel waters, P concentrations increment occurred leading to the formation of trophic gradient from the open sea towards the coast. As marine sediment presents the ultimate sink for particulate organic P from the water column, as well as for inorganic P forms, knowledge about distribution of different sediment P species is of great importance for understanding the burial, diagenesis and environmental geochemical significance of P. This paper presents results of P distribution at the eastern Adriatic sites of different trophic status (open sea, channel, estuary, semi-enclosed bay under the anthropogenic influence and fish farms) during 2002-2012. In the water column dissolved and particulate inorganic and organic P were analyzed. In all sediments total phosphorus (organic and inorganic P) was determined, while at certain sites beside organic P, inorganic P forms were examined using modified SEDEX methods (P in biogenic - P-FD; authigenic - P-AUT and in detrital apatite - P-DET; phosphorus bound to iron oxides and hydroxides - P-Fe). Various geochemical variables in the water column and sediment (HPO42- concentration, sediment redox potential, granulometric composition, carbonate content, iron, organic carbon and total nitrogen content) were also investigated. Results proved total P concentrations range between 3 and 161 µmol g-1, with highest values at sites under the strong anthropogenic impact including fish farms, estuaries and bay areas. Major inorganic P species in the eastern Adriatic was P-Fe form. Fish debris P species P-FD, prevailed in

  14. Tephrostratigraphy of the last 170 ka in sedimentary successions from the Adriatic Sea

    NASA Astrophysics Data System (ADS)

    Calanchi, Natale; Dinelli, Enrico

    2008-10-01

    In this study are discussed new SEM-EDS analyses performed on glass shards from five cores collected in the Central Adriatic Sea and two cores recovered from the South Adriatic Sea. A total of 26 tephra layers have been characterized and compared with the geochemical features of terrestrial deposits and other tephra archives in the area (South Adriatic Sea and Lago Grande di Monticchio, Vulture volcano). The compositions are compatible with either a Campanian or a Roman provenance. The cores, located on the Central Adriatic inner and outer shelf, recorded tephra referred to explosive events described in the literature: AP3 (sub-Plinian activity of the Somma-Vesuvius, 2710 ± 60 14C years BP); Avellino eruption (Somma-Vesuvius, 3548 ± 129 14C years BP); Agnano Monte Spina (Phlegrean Fields, 4100 ± 400 years BP); Mercato eruption (Somma-Vesuvius, 8010 ± 35 14C years BP; Agnano Pomici Principali eruption (Phlegrean Fields, 10,320 ± 50 14C years BP); Neapolitan Yellow Tuff (Phlegrean Fields, 12,100 ± 170 14C years BP). Some of these layers were also observed in the South Adriatic core IN68-9 in addition to younger ( AP2, sub-Plinian eruption, Somma-Vesuvius, 3225 ± 140 14C years BP), and older layers ( Pomici di Base eruption, Somma-Vesuvius, 18,300 ± 150 14C years BP). Significant is the tephra record of core RF95-7 that, for the first time in the Adriatic Sea, reports the occurrence of tephra layers older than 60 ka: the well known Mediterranean tephra layers X2 (ca. 70 ka), W1 (ca. 140 ka) and V2 (Roman origin, ca. 170 ka) as well as other tephra layers attributed, on the basis of geochemistry and biostratigraphy, to explosive eruptions occurred at Vico (138 ± 2 and 151 ± 3 ka BP) and Ischia (147-140 ka BP). Previous tephra correlations performed on other cores in the Central Adriatic Sea were also critically revised according to new available data, and integrated with the results of this study for a correlation at a regional scale. The most important key

  15. Sediment dynamics in the Adriatic Sea investigated with coupled models

    USGS Publications Warehouse

    Sherwood, Christopher R.; Book, Jeffrey W.; Carniel, Sandro; Cavaleri, Luigi; Chiggiato, Jacopo; Das, Himangshu; Doyle, James D.; Harris, Courtney K.; Niedoroda, Alan W.; Perkins, Henry; Poulain, Pierre-Marie; Pullen, Julie; Reed, Christopher W.; Russo, Aniello; Sclavo, Mauro; Signell, Richard P.; Traykovski, Peter A.; Warner, John C.

    2004-01-01

    Several large research programs focused on the Adriatic Sea in winter 2002-2003, making it an exciting place for sediment dynamics modelers (Figure 1). Investigations of atmospheric forcing and oceanic response (including wave generation and propagation, water-mass formation, stratification, and circulation), suspended material, bottom boundary layer dynamics, bottom sediment, and small-scale stratigraphy were performed by European and North American researchers participating in several projects. The goal of EuroSTRATAFORM researchers is to improve our ability to understand and simulate the physical processes that deliver sediment to the marine environment and generate stratigraphic signatures. Scientists involved in the Po and Apennine Sediment Transport and Accumulation (PASTA) experiment benefited from other major research programs including ACE (Adriatic Circulation Experiment), DOLCE VITA (Dynamics of Localized Currents and Eddy Variability in the Adriatic), EACE (the Croatian East Adriatic Circulation Experiment project), WISE (West Istria Experiment), and ADRICOSM (Italian nowcasting and forecasting) studies.

  16. Coupled Air-ocean Nested Modeling Studies Of The Adriatic Sea

    NASA Astrophysics Data System (ADS)

    Pullen, J.; Doyle, J.; Hodur, R.; Cummings, J.

    We have conducted simulations of the Adriatic Sea using the Navy Coastal Ocean Model (NCOM), with surface forcing provided by the atmospheric component of the Coupled Ocean/Atmosphere Mesoscale Prediction System (COAMPS). Our aim is to document and investigate the response pattern of the Adriatic to the complex combined forcing of the bora winds and strong Po River run-off. Separate three- dimensional multivariate optimum interpolation (MVOI) analysis techniques are used to generate the initial conditions for both COAMPS and NCOM. First, we used a 6-km NCOM grid over the entire Mediterranean Sea, with forcing supplied by sur- face stresses from a 27-km COAMPS grid, also covering the entire Mediterranean Sea area. Both the atmospheric and ocean fields produced were part of independent 12-hour incremental data assimilation cycles over the time period of interest. The re- sulting NCOM forecasts were then used as lateral boundary conditions for a series of higher resolution (2 km) NCOM forecasts of the Adriatic Sea. In these forecasts, a set of surface stress fields from COAMPS, using a nested 4 km grid centered over the Adriatic Sea, were used to force the NCOM high-resolution ocean nest. In addition, the 2 km Adriatic Sea model is forced by observed daily river discharge values from the Po River. We have focused on the time period of winter and spring 2001 when there were several bora wind events documented by the pilot program observations taken in preparation for the fall and winter 2002-2003 Adriatic Current Experiment (ACE). In addition, we analyze results from a multi-month simulation in fall/winter 1999 to establish circu- lation patterns that may appear during the upcoming observational season. The ACE observations will include ADCP's, moored buoys, CTD sections, and radar sites. The observational programs will generate much data about the circulation of this shallow sea subjected to river floods and strong bora wind events. The main goals of our work are to

  17. Mediterranean sea level variations.

    NASA Astrophysics Data System (ADS)

    Vigo, I.; Sánchez Reales, J. M.; García, D.; Chao, B. F.

    2009-04-01

    In this work we report an updated study of the sea level variations for the Mediterranean sea for the period from October 1992 to January 2008. The study addresses two mayor issues: (i)The analysis of the spatial and temporal variability of sea surface height (SSH) from radar altimetry measurements (from TOPEX/Poseidon (T/P) + Jason-1, etc.). We use EOF analysis to explain most of its interannual variation, and how the different basins interact. (ii) The analysis of dynamics and balance of water mass transport for the whole period. We estimate the steric SSH by combining the steric SSH estimated from temperature and salt profiles simulated by the ECCO model with time-variable gravity (TVG) data (from GRACE) for the Mediterranean Sea. The estimated steric SSH together with the SSH obtained from altimetry allow for a more realistic estimation of the water mass variations in the Mediterranean for the whole period.

  18. Bacterial diversity in the South Adriatic Sea during a strong, deep winter convection year.

    PubMed

    Korlević, M; Pop Ristova, P; Garić, R; Amann, R; Orlić, S

    2015-03-01

    The South Adriatic Sea is the deepest part of the Adriatic Sea and represents a key area for both the Adriatic Sea and the deep eastern Mediterranean. It has a role in dense water formation for the eastern Mediterranean deep circulation cell, and it represents an entry point for water masses originating from the Ionian Sea. The biodiversity and seasonality of bacterial picoplankton before, during, and after deep winter convection in the oligotrophic South Adriatic waters were assessed by combining comparative 16S rRNA sequence analysis and catalyzed reporter deposition-fluorescence in situ hybridization (CARD-FISH). The picoplankton communities reached their maximum abundance in the spring euphotic zone when the maximum value of the chlorophyll a in response to deep winter convection was recorded. The communities were dominated by Bacteria, while Archaea were a minor constituent. A seasonality of bacterial richness and diversity was observed, with minimum values occurring during the winter convection and spring postconvection periods and maximum values occurring under summer stratified conditions. The SAR11 clade was the main constituent of the bacterial communities and reached the maximum abundance in the euphotic zone in spring after the convection episode. Cyanobacteria were the second most abundant group, and their abundance strongly depended on the convection event, when minimal cyanobacterial abundance was observed. In spring and autumn, the euphotic zone was characterized by Bacteroidetes and Gammaproteobacteria. Bacteroidetes clades NS2b, NS4, and NS5 and the gammaproteobacterial SAR86 clade were detected to co-occur with phytoplankton blooms. The SAR324, SAR202, and SAR406 clades were present in the deep layer, exhibiting different seasonal variations in abundance. Overall, our data demonstrate that the abundances of particular bacterial clades and the overall bacterial richness and diversity are greatly impacted by strong winter convection. PMID:25548042

  19. Bacterial Diversity in the South Adriatic Sea during a Strong, Deep Winter Convection Year

    PubMed Central

    Korlević, M.; Pop Ristova, P.; Garić, R.; Amann, R.

    2014-01-01

    The South Adriatic Sea is the deepest part of the Adriatic Sea and represents a key area for both the Adriatic Sea and the deep eastern Mediterranean. It has a role in dense water formation for the eastern Mediterranean deep circulation cell, and it represents an entry point for water masses originating from the Ionian Sea. The biodiversity and seasonality of bacterial picoplankton before, during, and after deep winter convection in the oligotrophic South Adriatic waters were assessed by combining comparative 16S rRNA sequence analysis and catalyzed reporter deposition-fluorescence in situ hybridization (CARD-FISH). The picoplankton communities reached their maximum abundance in the spring euphotic zone when the maximum value of the chlorophyll a in response to deep winter convection was recorded. The communities were dominated by Bacteria, while Archaea were a minor constituent. A seasonality of bacterial richness and diversity was observed, with minimum values occurring during the winter convection and spring postconvection periods and maximum values occurring under summer stratified conditions. The SAR11 clade was the main constituent of the bacterial communities and reached the maximum abundance in the euphotic zone in spring after the convection episode. Cyanobacteria were the second most abundant group, and their abundance strongly depended on the convection event, when minimal cyanobacterial abundance was observed. In spring and autumn, the euphotic zone was characterized by Bacteroidetes and Gammaproteobacteria. Bacteroidetes clades NS2b, NS4, and NS5 and the gammaproteobacterial SAR86 clade were detected to co-occur with phytoplankton blooms. The SAR324, SAR202, and SAR406 clades were present in the deep layer, exhibiting different seasonal variations in abundance. Overall, our data demonstrate that the abundances of particular bacterial clades and the overall bacterial richness and diversity are greatly impacted by strong winter convection. PMID:25548042

  20. The PAH level, distribution and composition in surface sediments from a Mediterranean lagoon: the Marano and Grado Lagoon (Northern Adriatic Sea, Italy).

    PubMed

    Acquavita, Alessandro; Falomo, Jari; Predonzani, Sergio; Tamberlich, Francesco; Bettoso, Nicola; Mattassi, Giorgio

    2014-04-15

    The Marano and Grado Lagoon is one of the best conserved transitional environment in the whole Mediterranean area. On the other hand, it suffers from industrial, agricultural and fisheries activities, which could have an important impact on its environmental quality. With the application of the WFD, the sediment chemical status was investigated. In this work, 16 polycyclic aromatic hydrocarbons included by the US EPA within the priority pollutants were considered. PAHs values ranged from non-detectable to 1056 ng g(-1) showing the highest contamination close to the Aussa-Corno River mouth, which received the industrial inputs. The contamination level was comparable to that observed in low contaminated sites of the Mediterranean region, and lower than the adjacent Gulf of Trieste. The ratios of selected PAHs congeners pointed out the prevalence of pyrolitic sources. Moreover, the application of the ERL/ERM displayed an environment, which should not have a potential biological impact. PMID:24492154

  1. Global and regional factors contributing to the past and future sea level rise in the Northern Adriatic Sea

    NASA Astrophysics Data System (ADS)

    Scarascia, Luca; Lionello, Piero

    2013-07-01

    This study aims at discussing evolution of Sea Level (SL) in the Northern Adriatic Sea for the 20th and 21st century. A Linear Regression Model (LRM) which aims at describing the effect of regional processes, is built and validated. This LRM computes the North Adriatic mean SL variations using three predictors: the Mean Sea Level Pressure (MSLP) in the Gulf of Venice, the mean Sea Temperature (ST) of the water column in the South Adriatic and the Upper Level Salinity (ULS) in the central part of the basin. SL data are provided by monthly values recorded at 7 tide gauges distributed along the Italian and Croatian coasts (available at the PSMSL, Permanent Service of Mean Sea Level). MSLP data are provided by the EMULATE data set. Mediterranean ST and ULS data are extracted from the MEDATLAS/2002 database. The study shows that annual SL variations at Northern Adriatic stations are very coherent, so that the Northern Adriatic SL can be reconstructed since 1905 on the basis of only two stations: Venice and Trieste. The LRM is found to be robust, very successful at explaining interannual SL variations and consistent with the physical mechanisms responsible for SL evolution. Results show that observed SL in the 20th century has a large trend, which cannot be explained by this LRM, and it is interpreted as the superposition of land movement and a remote cause (such as polar ice melting). When the LRM is used with the MSLP, ST and ULS from climate model projections for the end of the 21st century (A1B scenario), it produces an SL rise in the range from 2.3 to 14.1 cm, with a best estimate of 8.9 cm. However, results show that the behavior of the remotely forced SL rise is the main source of future SL uncertainty and extrapolating its present trend to the future would expand the range of SL uncertainty from 14 to 49 cm.

  2. Effects of winter convection on the deep layer of the Southern Adriatic Sea in 2012

    NASA Astrophysics Data System (ADS)

    Bensi, M.; Cardin, V.; Rubino, A.; Notarstefano, G.; Poulain, P. M.

    2013-11-01

    We analyze aspects concerning the thermohaline changes observed in the near-bottom layer of the Southern Adriatic Pit (SAP), in the Eastern Mediterranean, after the arrival of abundant and exceptionally dense water (σθ > 30 kg m-3) produced in the shallow Northern Adriatic Sea during winter 2012. For this purpose, we use temperature (T), salinity (S), and current time series collected at the E2M3A deep-ocean observatory of the Southern Adriatic, and Conductivity-Temperature-Depth data obtained both in the Southern and Middle Adriatic from freely drifting profiling floats. The dense water produced in the Northern Adriatic arrived in the central and deepest part of the SAP as a series of individual pulses starting on 10 March 2012; while, a stronger and prolonged signal that significantly modified the local deep water stratification arrived after 10 April 2012. As a consequence, T and S suddenly decreased (≈0.15°C and ≈0.015), thus interrupting positive T and S bottom trends observed during the previous 5 years and producing a density increase of ≈0.02 kg m-3. Such variability has been rarely observed in the area. We ascribe its occurrence to the concomitance of exceptionally harsh and long-lasting Bora wind, scarce precipitation, and low river discharge over the Northern Adriatic during winter 2011/2012. Eventually, this newly formed AdDW reached the Strait of Otranto during July 2012. Its characteristics profoundly differed from those observed in the previous decade. Hence, a noticeable variability in structure and circulation of the abyssal layers of the Ionian basin is likely to occur in the near future.

  3. Adriatic and Black Sea level in the 20th century and projection to the end of the 21st century.

    NASA Astrophysics Data System (ADS)

    Scarascia, Luca; Lionello, Piero

    2015-04-01

    Adriatic and Black Sea are semi-enclosed basins characterized by densely populated coasts, industrial compounds and a rich cultural and historical heritage. It appears to be crucial, for the management and the protection of their coastlines, to understand how much they will be impacted by the global sea level (SL) rise, projected by the end of this century. The aim of this work is to develop a method that allows to estimate to which extent the SL of the two basins will depart from the mean global level. The future evolution of global sea level is not a meaningful indicator at this regional scale and past deviations, due to local factors of the Adriatic and Black Sea levels from the global one, have been observed. The Adriatic Sea is the basin of the Mediterranean Sea best covered by past SL observations. In fact, for the Adriatic Sea is possible to obtain, by statistical method based on PCA and Least square Method, a seamless and long time series (from 1900 to 2009) using records of 7 mareographic stations located along the Italian and Croatian coasts (from PSMSL database). Satellite data of SL are available for the whole Mediterranean from 1993 to 2012 and they show a very high correlation (rho > 0.9) with Adriatic time series based on mareographic records. The SL time series of the 20th century in the Black Sea is computed using data of 4 stations, which are available in the PSMSL (Permanent Service for Mean Sea Level) archive, located on the north-east coast. This time series shows a lower correlation (rho about 0.5) with satellite data than in the case of Adriatic Sea. Further it shows a higher interannual variability. All the time series are considered after the subtraction of the Inverse Barometer (IB) effect. A statistical approach, based on a multivariate linear regression model, is used to investigate the link between SL anomaly, computed as the difference between the regional SL and global SL, and three large scale climate variables (sea level pressure

  4. Oil spill hazard from dispersal of oil along shipping lanes in the Southern Adriatic and Northern Ionian Seas.

    PubMed

    Liubartseva, S; De Dominicis, M; Oddo, P; Coppini, G; Pinardi, N; Greggio, N

    2015-01-15

    An assessment of hazard stemming from operational oil ship discharges in the Southern Adriatic and Northern Ionian (SANI) Seas is presented. The methodology integrates ship traffic data, the fate and transport oil spill model MEDSLIK-II, coupled with the Mediterranean Forecasting System (MFS) ocean currents, sea surface temperature analyses and ECMWF surface winds. Monthly and climatological hazard maps were calculated for February 2009 through April 2013. Monthly hazard distributions of oil show that the zones of highest sea surface hazard are located in the southwestern Adriatic Sea and eastern Ionian Sea. Distinctive "hot spots" appear in front of the Taranto Port and the sea area between Corfu Island and the Greek coastlines. Beached oil hazard maps indicate the highest values in the Taranto Port area, on the eastern Greek coastline, as well as in the Bari Port area and near Brindisi Port area. PMID:25455790

  5. Investigating the northern Adriatic Sea ecosystem state with a very high resolution model

    NASA Astrophysics Data System (ADS)

    Mattia, Gelsomina; Zavatarelli, Marco; Lovato, Tomas

    2015-04-01

    The northern Adriatic Sea ecosystem dynamics is simulated using the coupling of the BFM (Biogeochemical Flux Model) with the NEMO (Nucleus for European Models of the Ocean) model. The modeling system is implemented at very high horizontal (~800 m) and vertical (95 z-level) resolution and is nested with a coarser scale Adriatic/Mediterranean model. Simulation in hindcast and projection mode are being executed and are aimed to evaluate the ecosystem attributes (vigor, organization, resilience), in order to understand the ecosystem state of the basin with respect to the so-called "Good Ecosystem State" (GES) as defined by the EU-MSF9 Directive. Skill of the model in replicating integrated environmental indices such as the EU-EEACS1023+ is also investigated. Finally the model is also open to an off-line coupling with an higher trophic level (HTL) model.

  6. Three Anisakis spp. isolated from toothed whales stranded along the eastern Adriatic Sea coast.

    PubMed

    Blažeković, Kristina; Pleić, Ivana Lepen; Đuras, Martina; Gomerčić, Tomislav; Mladineo, Ivona

    2015-01-01

    Knowledge concerning cetacean ecology in the Mediterranean is limited but important for sustainable planning and enforcement of appropriate conservation measures. Any information that might help to elucidate their ecology is essential. We explored the population and genetic structures of Anisakis spp. nematodes isolated from four toothed whale species - bottlenose dolphins (Tursiops truncatus), striped dolphins (Stenella coeruleoalba), Risso's dolphins (Grampus griseus) and Cuvier's beaked whales (Ziphius cavirostris) - stranded along the eastern Adriatic Sea coast (1990-2012) to reveal more information on host ecological patterns. Lower parasite prevalence was observed in resident dolphin species compared with occasionally occurring species, as well as in young compared with adult dolphins, indicating different feeding habits related to age. No unequivocal relationship between the biological traits of a host (age, body length, body mass and blubber depth) and Anisakis population parameters was observed. Phylogenetic analysis revealed a new geographical record of Anisakis simplex sensu stricto (1.96%) and Anisakis physeteris (1.31%) in the Adriatic Sea in addition to resident Anisakis pegreffii (96.73%). In an assessment of the Adriatic Sea and oceans worldwide, the genetic structure of Anisakis revealed that A. pegreffii populations do not differ among various final host species but do differ with respect to geographical location in contrast to previously accepted Anisakis panmixia. PMID:25449948

  7. Biocomplexity in Populations of European Anchovy in the Adriatic Sea

    PubMed Central

    Ruggeri, Paolo; Splendiani, Andrea; Occhipinti, Giulia; Fioravanti, Tatiana; Santojanni, Alberto; Leonori, Iole; De Felice, Andrea; Arneri, Enrico; Procaccini, Gabriele; Catanese, Gaetano; Tičina, Vjekoslav; Bonanno, Angelo; Nisi Cerioni, Paola; Giovannotti, Massimo; Grant, William Stewart; Caputo Barucchi, Vincenzo

    2016-01-01

    The sustained exploitation of marine populations requires an understanding of a species' adaptive seascape so that populations can track environmental changes from short- and long-term climate cycles and from human development. The analysis of the distributions of genetic markers among populations, together with correlates of life-history and environmental variability, can provide insights into the extent of adaptive variation. Here, we examined genetic variability among populations of mature European anchovies (n = 531) in the Adriatic (13 samples) and Tyrrhenian seas (2 samples) with neutral and putative non-neutral microsatellite loci. These genetic markers failed to confirm the occurrence of two anchovy species in the Adriatic Sea, as previously postulated. However, we found fine-scale population structure in the Adriatic, especially in northern areas, that was associated with four of the 13 environmental variables tested. Geographic gradients in sea temperature, salinity and dissolved oxygen appear to drive adaptive differences in spawning time and early larval development among populations. Resolving adaptive seascapes in Adriatic anchovies provides a means to understand mechanisms underpinning local adaptation and a basis for optimizing exploitation strategies for sustainable harvests. PMID:27074008

  8. Biocomplexity in Populations of European Anchovy in the Adriatic Sea.

    PubMed

    Ruggeri, Paolo; Splendiani, Andrea; Occhipinti, Giulia; Fioravanti, Tatiana; Santojanni, Alberto; Leonori, Iole; De Felice, Andrea; Arneri, Enrico; Procaccini, Gabriele; Catanese, Gaetano; Tičina, Vjekoslav; Bonanno, Angelo; Nisi Cerioni, Paola; Giovannotti, Massimo; Grant, William Stewart; Caputo Barucchi, Vincenzo

    2016-01-01

    The sustained exploitation of marine populations requires an understanding of a species' adaptive seascape so that populations can track environmental changes from short- and long-term climate cycles and from human development. The analysis of the distributions of genetic markers among populations, together with correlates of life-history and environmental variability, can provide insights into the extent of adaptive variation. Here, we examined genetic variability among populations of mature European anchovies (n = 531) in the Adriatic (13 samples) and Tyrrhenian seas (2 samples) with neutral and putative non-neutral microsatellite loci. These genetic markers failed to confirm the occurrence of two anchovy species in the Adriatic Sea, as previously postulated. However, we found fine-scale population structure in the Adriatic, especially in northern areas, that was associated with four of the 13 environmental variables tested. Geographic gradients in sea temperature, salinity and dissolved oxygen appear to drive adaptive differences in spawning time and early larval development among populations. Resolving adaptive seascapes in Adriatic anchovies provides a means to understand mechanisms underpinning local adaptation and a basis for optimizing exploitation strategies for sustainable harvests. PMID:27074008

  9. A Self-Organizing Maps approach to assess the wave climate of the Adriatic Sea

    NASA Astrophysics Data System (ADS)

    Barbariol, Francesco; Marcello Falcieri, Francesco; Scotton, Carlotta; Benetazzo, Alvise; Bergamasco, Andrea; Bergamasco, Filippo; Bonaldo, Davide; Carniel, Sandro; Sclavo, Mauro

    2015-04-01

    The assessment of wave conditions at sea is fruitful for many research fields in marine and atmospheric sciences and for the human activities in the marine environment. To this end, in the last decades the observational network, that mostly relies on buoys, satellites and other probes from fixed platforms, has been integrated with numerical models outputs, which allow to compute the parameters of sea states (e.g. the significant wave height, the mean and peak wave periods, the mean and peak wave directions) over wider regions. Apart from the collection of wave parameters observed at specific sites or modeled on arbitrary domains, the data processing performed to infer the wave climate at those sites is a crucial step in order to provide high quality data and information to the community. In this context, several statistical techniques has been used to model the randomness of wave parameters. While univariate and bivariate probability distribution functions (pdf) are routinely used, multivariate pdfs that model the probability structure of more than two wave parameters are hardly managed. Recently, the Self-Organizing Maps (SOM) technique has been successfully applied to represent the multivariate random wave climate at sites around the Iberian peninsula and the South America continent. Indeed, the visualization properties offered by this technique allow to get the dependencies between the different parameters by visual inspection. In this study, carried out in the frame of the Italian National Flagship Project "RITMARE", we take advantage of the SOM technique to assess the multivariate wave climate over the Adriatic Sea, a semi-enclosed basin in the north-eastern Mediterranean Sea, where winds from North-East (called "Bora") and South-East (called "Sirocco") mainly blow causing sea storms. By means of the SOM techniques we can observe the multivariate character of the typical Bora and Sirocco wave features in the Adriatic Sea. To this end, we used both observed and

  10. Jabuka island (Central Adriatic Sea) earthquakes of 2003

    NASA Astrophysics Data System (ADS)

    Herak, Davorka; Herak, Marijan; Prelogović, Eduard; Markušić, Snježana; Markulin, Željko

    2005-04-01

    We present analyses of one of the strongest earthquake sequences ever recorded within the Adriatic microplate, which occurred near the Jabuka island in the very centre of the Adriatic Sea. The mainshock (29 March 2003, 17:42, ML=5.5) was preceded by over 150 foreshocks, and followed by many aftershocks, over 4600 of which were recorded on the closest station HVAR (about 90 km to the east). As the epicentre was in the open sea and due to the absence of nearby stations, we were able to confidently locate only 597 events. Hypocentral locations were computed by a grid-search algorithm after seven iterations of refining hypocentres and adjusting station corrections. Epicentres lie in a well-defined area of about 300 km 2, just to the W and NW of the Jabuka island. The vertical cross-sections reveal that hypocentres dip to the NE, closely matching faults from the Jabuka-Andrija fault system, as identified on the available reflection profiles in the area. The fault-plane solution of the main shock based on the first-motion polarity readings agrees well with the CMT solutions and indicates faulting caused by a S-N directed tectonic pressure, on a reverse, dip-slip fault. This is in very good agreement with the seismotectonic framework of the area. These earthquakes are important as they identify the Jabuka-Andrija fault system as an active one, which can significantly influence seismic hazard on the islands in the central Adriatic archipelago and on the Croatian coast between Zadar and Split. Along with several other sequences which occurred in the last two decades, they force us to change our notion of Adria as nearly aseismic, compact and rigid block. In fact, it turns out that recent seismicity of the Central Adriatic Sea is comparable to the seismicity of several well known earthquake-prone areas in the circum-Adriatic region.

  11. Coflexip installs flexible water line in Adriatic Sea

    SciTech Connect

    Not Available

    1990-07-01

    This paper reports on the design, manufacture, transport and installation of a submarine pipe line network. The network would transport potable water from Yugoslavia's Dubroynil and Peljesac peninsula to the islands of Elafiti and Mljet, popular resort areas in the Adriatic Sea. The pipe line network consists of five separate 8-in. ID flexible lines, each 10 mi long. The pipe is made of thermoplastic tubing, a steel carcass and double crossword armor. The tubing is suitable for potable water service.

  12. Waterspouts of the Adriatic, Ionian and Aegean Sea and their meteorological environment

    NASA Astrophysics Data System (ADS)

    Sioutas, Michalis V.; Keul, Alexander G.

    2007-02-01

    The synoptic and mesoscale conditions associated with waterspout occurrence in the Adriatic, Ionian and Aegean Sea are examined in an attempt to quantitatively assess the meteorological environment favourable to the development of waterspouts. For this study, synoptic circulation patterns have been examined for 28 waterspout events in the central-eastern Mediterranean. The waterspouts were reported within the summer and fall of 2002, from July to November, a period of unusually high whirlwind activity. The Adriatic was most active during July, August and September and the Ionian and Aegean during September, October and November. Of the examined waterspout cases, 13 out of the total of 28 were found to be fair-weather waterspouts, while 15 represent tornadic events. For waterspout days, the frequency and distribution of four basic synoptic types, namely, south-west flow (SW), long-wave trough (LW), closed low (CLOSED) and short-wave trough (SWT), were investigated. The particular synoptic features that contributed to the development of waterspout activity were examined, based on five selected waterspout case studies. The mesoscale environment was explored using thermodynamic indices, moisture and wind parameters as derived by operational soundings from the nearest sites (preferably upwind) and closest in time to the waterspout occurrences. The results present an analysis of waterspout types in conjunction to thermodynamic and wind parameters for the purpose of determining synoptic patterns and mesoscale conditions most relevant to waterspout occurrences in these sea areas of the Mediterranean.

  13. Adriatic Sea Decision Support System (ADRI-DSS)

    NASA Astrophysics Data System (ADS)

    Coppini, Giovanni; Lyubartsev, Vladyslav; Pinardi, Nadia; Montanari, Giuseppe; Rinaldi, Attilio; Serra, Stefano; Santoleri, Rosalia

    2010-05-01

    The Adriatic Sea decision support system (ADRI-DSS) consists of an on-line service built upon a set of integrated operational oceanography products. ADRI-DSS integrates the Adriatic Sea monitoring and forecasting system (AFS) with local in-situ observations and is built to support the Emilia-Romagna coastal monitoring system for marine environment and ecosystem health. The target user is the Regional Environment Prevention Agency from Emilia-Romagna (Italy) called ARPA-EMR. Specifically ADRI-DSS will support the daily action of the oceanographic section of ARPA-EMR called ARPA-DAPHNE providing all the available products (forecast, observations, simulations) from Adriatic Forecasting System. The product is shaped as required by the user and moreover ADRI-DSS also integrates with the routinely observations that the user carry out on a weekly basis. The system has been designed through the interaction with ARPA-DAPHNE and consists of a online portal containing simulation and forecast for the relevant north Adriatic region. Moreover the model products are compared with in-situ observations of temperature and salinity collected by the ARPA-DAPHNE itself. In the coming future also satellite observations and indicators will be made available by ADRI-DSS. The final aim of ADRI-DSS is to integrate selected products from the AFS with the insitu and satellite observation to support the monitoring activities of ARPA-DAPNHE and to improve ARPA-DAPHNE capabilities for the Emilia-Romagna marine environment status assessment. ADRI-DSS has been developed within ECOOP project (European COastal-shelf sea OPerational Observing and forecasting system Integrated Project). ADRI-DSS is a web-based application available via internet browsers with JavaScript capability. The server part is implemented on PHP (data management) and NCL (graphics production). The NCL is NCAR Command Language, a free interpreted language designed specifically for scientific data processing and visualization, see

  14. Thermohaline variability in the Adriatic and Northern Ionian Seas observed from the Argo floats during 2010-2014

    NASA Astrophysics Data System (ADS)

    Kovačević, Vedrana; Ursella, Laura; Gačić, Miroslav; Notarstefano, Giulio; Menna, Milena; Bensi, Manuel; Civitarese, Giuseppe; Poulain, Pierre-Marie

    2015-04-01

    The Adriatic Sea is the northernmost basin of the Eastern Mediterranean Sea (EMed). At its southern end, the basin communicates with the adjacent Ionian Sea through the 80 km wide and 850 m deep Strait of Otranto. Due to the river discharge in the north and due to the strong winter cooling, the Adriatic is both a dilution basin and the dense water formation region. The basin-wide circulation is cyclonic. The circulation is however, energetic also at smaller spatial and temporal scales, and several circulation cells and mesoscale features are regularly observed equally along the littoral and in the open sea. The North Adriatic Dense Water (NAdDW) formed during winter is the densest water of the whole Mediterranean Sea (up to 1060 kg/m3). It flows as a density driven bottom current from the northern shelf toward south, filling the deep layers of the middle and southern Adriatic pits. The deep open-sea area of the South Adriatic Pit (SAP, 1200 m) feels the influence of a water mass exchange through the Strait of Otranto. Specifically, it receives salty and warm surface and Levantine Intermediate Waters from the Ionian Sea. Through the open-sea winter convection that homogenizes and ventilates 400-800 m thick upper water column, this salty water contributes to the formation of the Adriatic Deep Water (AdDW, 1029.17-1029.20 kg/m3), which is not as dense as the NAdDW. Both dense waters eventually mix and spill across the sill ventilating the deep and bottom layers of the Ionian Sea, and driving the deep thermohaline cell of the EMed. Thermohaline properties of the Adriatic Sea vary at wide spatial and temporal scales, and this in turn affects the properties of its dense waters. The long-term scales are of a particular interest, as they are often associated with the biogeochemical and biotic variability such as intrusion of alien species into the Adriatic Sea and interconnection with the adjacent Ionian basin. Due to the extremely variable meteo- and climatic conditions

  15. Development of a geotechnical and pile driving database, Adriatic Sea

    SciTech Connect

    Carpaneto, R.; Paoletti, L.; Guaita, P.; Pratico, A.

    1996-12-31

    The paper presents a geotechnical and pile driving data base relevant to offshore installations in the Adriatic Sea. The paper discusses sources of information, structure, content, and engineering applications of the data base. Data available from Agip`s platform installations in the Adriatic was reviewed, and 20 representative platforms were chosen. Two relational data bases were created, for geotechnical and installation data respectively. The data bases provide a comprehensive and organized source of information about past experience in the area. Such experience is now quickly available for geotechnical engineering activities. As a main application of the data bases, information was processed to make data sets for training Artificial Neural Networks (ANN) to predict pile driveability. It is envisioned that the data bases will also be used in ongoing installation program design.

  16. Multi-Meteotsunami Event in the Adriatic Sea Generated by Atmospheric Disturbances of 25-26 June 2014

    NASA Astrophysics Data System (ADS)

    Šepić, Jadranka; Međugorac, Iva; Janeković, Ivica; Dunić, Natalija; Vilibić, Ivica

    2016-01-01

    A series of meteotsunamis hit a few locations in the Mediterranean and Black Seas during 22-27 June 2014. Meteotsunamis were particularly numerous on 25 and 26 June in the Adriatic Sea, where at least six harbours and bays were stricken by powerful waves: strongest events occurred in Vela Luka (Korčula Island), a known meteotsunami hot-spot, where waves reached height of ~3 m, and in Rijeka dubrovačka Bay, where strong ~5 m/s currents accompanied ~2.5 m high waves. Intensification of high-frequency sea level activity was observed at both the eastern and western Adriatic tide gauge stations, with maximum recorded wave heights reaching ~68 cm (Ortona, Italy). A series of individual air pressure disturbances characterized by pronounced rates of air pressure change (up to 2.4 hPa/5 min), limited spatial extent (~50 km) and high temporal variability, propagated over the Adriatic on 2 days in question. Numerical hydrodynamic model SCHISM forced by measured and idealised air pressure disturbances was utilised to reproduce the observed Adriatic sea level response. Several important conclusions were reached: (1) meteotsunamis occurring at various parts of the coast were generated by different atmospheric air pressure disturbances; (2) topographic influence can be removed from sea level spectra by computing spectral signal-to-background ratios; the result, being related to the external forcing, resembles atmospheric pressure spectra; (3) sea response is strongly dependant on details of atmospheric forcing; and (4) over complex bathymetries, like the middle and south Adriatic ones, numerous effects, including Proudman resonance, edge waves, strong topographical enhancement and refractions on the islands placed on the pathway of atmospheric disturbances should be taken into account to fully understand meteotsunami generation and dynamics. An in-depth numerical study is planned to supplement the latter conclusion and to quantify contribution of each process.

  17. Mass mortality events of the coral Balanophyllia europaea (Scleractinia, Dendrophylliidae) in the Mljet National Park (eastern Adriatic Sea) caused by sea temperature anomalies

    NASA Astrophysics Data System (ADS)

    Kružić, P.; Popijač, A.

    2015-03-01

    Recurrent climate-induced mass mortalities of marine animals have been recorded in the Mediterranean Sea over the past 15 years. These mortality outbreaks have been associated with positive thermal anomalies. In this study, we assessed long-term (from 2003 to 2013) responses of the temperate coral Balanophyllia europaea to increasing seawater temperatures in the Mljet National Park in the Adriatic Sea (Northern Mediterranean Sea) and described the relationship between recurrent mortality events and sea temperature regimes in the southern Adriatic Sea. Our results indicate that polyp bleaching and tissue necrosis caused the observed mortality. The first observations of B. europaea mortality within the study area in the Mljet NP were in early September 2003. The Mediterranean area experienced high temperatures and hydrographic stability over a period of several weeks throughout that summer, which resulted in a mass mortality event. In the Mljet National Park, the highest impact of mass mortality started during the exceptionally hot summer of 2012, representing one of the most severe mass mortality events ever observed in the Adriatic Sea. In 2012, sea temperatures at a 5 m depth during the summer period (from June to September) ranged from 24.44 to 30.16 °C in the Mljet NP. The northern sites in the Mljet NP were highly impacted, with up to 80 % of B. europaea specimens affected by necrosis, while the southern sites displayed the highest impact, with 90-100 % of affected individuals. Without any coral adaptation to warming and under the present climate-warming trend, new mass mortality events may occur in the near future, possibly causing a major coral biodiversity crisis in the Mediterranean Sea.

  18. Gradients of benthic pelagic coupling and carbon budgets in the Adriatic and Northern Ionian Sea

    NASA Astrophysics Data System (ADS)

    Giordani, P.; Helder, W.; Koning, E.; Miserocchi, S.; Danovaro, R.; Malaguti, A.

    2002-06-01

    The Adriatic sea is generally viewed as a long bay in the Central Mediterranean, stretching SE to NW for 800 km, from the Strait of Otranto to the Gulf of Venice, with an extremely long, geometrically complex coastline, creating a high diversity of hydrodynamic and sedimentary environments. The seafloor slopes down from the North shallow shelf (mean depth 35 m) through the middle Adriatic depression (250 m depth in the Pomo Pit) to the bathyal reached in the Southern Adriatic pit (1260 m). Typical physiographic and climatic features strongly influence biological productivity. The productivity of the Northern Adriatic is among the highest in the Mediterranean, while it becomes lower in the offshore waters of the Central and Southern subbasins, defining clear oligotrophic and benthic-pelagic coupling gradients from the Northern to the Southern edge of the basin. Assessing the benthic response to particulate fluxes of organic matter from the photic layer was a target of the EU-MATER Project. The applied methodological strategy involved measurements of primary production by 14C in situ incubation technique, of particulate fluxes through the water column by moored sediment traps, of sediment community oxygen consumption (SCOC) by in situ and on-deck incubations, and of carbon burial fluxes at three sites in the Southern Adriatic (A1), the Otranto Strait (O2) and the Ionian sea (I1), along the main pathway of outflowing water masses. In this paper, yearly budget calculations of carbon are presented for stations, selected as being representative of wider areas in the three subbasins, to give a picture of the Adriatic basin as a whole. Data from the Northern basin, obtained by the same methodology, come from previous research programmes carried out in the framework of EU Marine projects (STEP/Adria and MTP 1/Euromarge AS). The carbon fraction reaching the seafloor was quantified as the sum of SCOC and burial fluxes and was compared to 14C primary production measurements in

  19. Self-Organizing Maps method in recent Adriatic Sea environmental studies: applications and perspectives

    NASA Astrophysics Data System (ADS)

    Mihanovic, H.; Vilibic, I.

    2014-12-01

    Herein we present three recent oceanographic studies performed in the Adriatic Sea (the northernmost arm of the Mediterranean Sea), where Self-Organizing Maps (SOM) method, an unsupervised neural network method capable of recognizing patterns in various types of datasets, was applied to environmental data. The first study applied the SOM method to a long (50 years) series of thermohaline, dissolved oxygen and nutrient data measured over a deep (1200 m) Southern Adriatic Pit, in order to extract characteristic deep water mass patterns and their temporal variability. Low-dimensional SOM solutions revealed that the patterns were not sensitive to nutrients but were determined mostly by temperature, salinity and DO content; therefore, the water masses in the region can be traced by using no nutrient data. The second study encompassed the classification of surface current patterns measured by HF radars over the northernmost part of the Adriatic, by applying the SOM method to the HF radar data and operational mesoscale meteorological model surface wind fields. The major output from this study was a high correlation found between characteristic ocean current distribution patterns with and without wind data introduced to the SOM, implying the dominant wind driven dynamics over a local scale. That nominates the SOM method as a basis for generating very fast real-time forecast models over limited domains, based on the existing atmospheric forecasts and basin-oriented ocean experiments. The last study classified the sea ambient noise distributions in a habitat area of bottlenose dolphin, connecting it to the man-made noise generated by different types of vessels. Altogether, the usefulness of the SOM method has been recognized in different aspects of basin-scale ocean environmental studies, and may be a useful tool in future investigations of understanding of the multi-disciplinary dynamics over a basin, including the creation of operational environmental forecasting systems.

  20. Floating debris in the Mediterranean Sea.

    PubMed

    Suaria, Giuseppe; Aliani, Stefano

    2014-09-15

    Results from the first large-scale survey of floating natural (NMD) and anthropogenic (AMD) debris (>2 cm) in the central and western part of the Mediterranean Sea are reported. Floating debris was found throughout the entire study area with densities ranging from 0 to 194.6 items/km(2) and mean abundances of 24.9 AMD items/km(2) and 6.9 NMD items/km(2) across all surveyed locations. On the whole, 78% of all sighted objects were of anthropogenic origin, 95.6% of which were petrochemical derivatives (i.e. plastic and styrofoam). Maximum AMD densities (>52 items/km(2)) were found in the Adriatic Sea and in the Algerian basin, while the lowest densities (<6.3 items/km(2)) were observed in the Central Tyrrhenian and in the Sicilian Sea. All the other areas had mean densities ranging from 10.9 to 30.7 items/km(2). According to our calculations, more than 62 million macro-litter items are currently floating on the surface of the whole Mediterranean basin. PMID:25127501

  1. Mass occurrence of the ctenophore Bolinopsis vitrea (L. Agassiz, 1860) in the nearshore southern Adriatic Sea (Kotor Bay, Montenegro).

    PubMed

    Lucic, Davor; Pestoric, Branka; Malej, Alenka; Lopez-Lopez, Lucia; Drakulovic, Dragana; Onofri, Vladimir; Miloslavic, Marijana; Gangai, Barbara; Onofri, Ivona; Benovic, Adam

    2012-08-01

    The ctenophore Bolinopsis vitrea has been rarely observed in the Mediterranean Sea. A bloom of B. vitrea is here reported for the first time in the southern Adriatic Sea in the spring and summer of 2009, together with its effect on the plankton of Kotor Bay. Ctenophores were found below 5 m depth only. Results of the investigation indicate that mass occurrence of B. vitrea could have a great impact on the Kotor Bay ecosystem. Their predation on copepods would reduce grazing pressure on phytoplankton, favouring an uncommon bloom of the latter. It is evident that B. vitrea are capable of altering rapidly the composition and biomass of coastal plankton communities when present in large masses. This first evidence of such events for this species may indicate changes in the functioning of marine ecosystems of the southern Adriatic. PMID:21912872

  2. Spreading patterns of the invasive Caulerpa cylindracea Sonder along the west Istrian Coast (northern Adriatic Sea, Croatia).

    PubMed

    Iveša, Ljiljana; Djakovac, Tamara; Devescovi, Massimo

    2015-06-01

    The northern Adriatic Sea represents the northernmost and thus the coldest biogeographic sector of the Mediterranean Sea. In 2004, the invasive green alga Caulerpa cylindracea was recorded for the first time in the northern Adriatic at a site of the west Istrian Coast. Until 2010, additional C. cylindracea mats have only formed up to 7 km northward from the first colonisation site. Subsequently, the alga was also recorded at sites widespread along the entire coast. Both the first 2004 colonisation event and the 2011-2014 colonisation of distant sites occurred during periods of winter seawater temperatures higher than 9 °C. In general, algal spreading was markedly slow. Approximately 10 years after the first record, C. cylindracea has affected less than 1% of the entire west Istrian coastline. The colonisation predominantly occurred in ports and urbanised bays (seaside resorts) suggesting that anthropogenic activities might enhance algal diffusion. PMID:25828676

  3. Long-term fluctuations in Cystoseira populations along the west Istrian Coast (Croatia) related to eutrophication patterns in the northern Adriatic Sea.

    PubMed

    Iveša, Ljiljana; Djakovac, Tamara; Devescovi, Massimo

    2016-05-15

    An exploration of historical data suggested that eutrophication patterns might drive long-term fluctuations in Cystoseira populations along the west Istrian Coast (northern Adriatic Sea, Croatia). The regimes of northern Italian rivers, which flow approximately 100km west of the study area, mainly modulate the eutrophication levels of the northern Adriatic Sea. A regression of Cystoseira populations from the 1970s through the 1990s corresponded to increased levels of eutrophication in the study area. During the late 1990s, the density of sea urchins, which are efficacious macroalgal predators, decreased, likely due to an intense formation of pelagic mucilage aggregates that resulted in mass mortality episodes of macrozoobenthic species. During the 2000-2013 period, an oligotrophication of the northern Adriatic formed the basis for the recovery of Cystoseira taxa, whose abundances from 2009 to 2013 were similar to those characterising the most flourishing Mediterranean Cystoseira assemblages. PMID:26975612

  4. A numerical study of the interannual variability of the Adriatic Sea (2000-2002).

    PubMed

    Oddo, Paolo; Pinardi, Nadia; Zavatarelli, Marco

    2005-12-15

    A free-surface, three-dimensional finite-difference numerical model based on the Princeton Ocean Model (POM) has been implemented in order to simulate the interannual variability of the Adriatic Sea circulation. The implementation makes use of an interactive surface momentum and heat flux computation that utilizes the European Centre for Medium-Range Weather Forecasts (ECMWF) 6-h analyses and the model predicted sea surface temperatures. The model is also nested at its open boundary with a coarse-resolution Mediterranean general circulation model, utilizing the same surface forcing functions. The simulation and analysis period spans 3 years (1 Jan 2000 to 31 Dec 2002) coinciding with the "Mucilage in the Adriatic and the Tyrrhenian" (MAT) Project monitoring activities. Model results for the simulated years show a strong interannual variability of the basin averaged proprieties and circulation patterns, linked to the atmospheric forcing variability and the Po river runoff. In particular, the years 2000 and 2002 are characterized by a weak surface cooling (with respect to the climatological value) and well-marked spring and autumn river runoff maxima. Conversely, 2001 is characterized by stronger wind and heat (autumn cooling) forcings but no river runoff autumn peak, even though the total amount of water inflow during winter and spring is sustained. The circulation is characterized by similar patterns in 2000 and 2002 but very different structures in 2001. During the latter, deep water is not formed in the northern Adriatic. A comparison with the observed data shows that the major model deficiencies are connected to the low salinity of the waters, probably connected to the missed inflow of salty Ionian waters of Aegean origin and to the numerical overestimation of the vertical mixing processes. PMID:16257438

  5. Applications of remote sensing for the evaluation of Adriatic Sea environmental conditions

    SciTech Connect

    Vitiello, F.; Borfecchia, F.; De Cecco, L.; Martini, S.

    1997-08-01

    The paper shows the remote sensing activities that ENEA is carrying out for the evaluation of Adriatic Sea environmental conditions and their modifications over the last fifteen years. The activities were requested by the Italian Research Ministry to gain knowledge of the circulation model of the Adriatic Sea and to understand what caused algae blooms in some of the last years. The Adriatic Sea is a high environmental risk sea, because its depth is low and a strong pollutant charge is coming into the sea from the Po river and from many other rivers of the NE coast of Italy. Processing of satellite images has covered the period from 1980 up to now and has allowed the reconstruction of modifications of the environmental conditions of the sea. The paper shows the first results obtained by remote sensing images processing that will be utilized for the database of the Adriatic Sea.

  6. Dolomite as a tracer for sediment transport and deposition on the northwestern Adriatic continental shelf (Adriatic Sea, Italy)

    NASA Astrophysics Data System (ADS)

    Ravaioli, Mariangela; Alvisi, Francesca; Vitturi, Laura Menegazzo

    2003-09-01

    Surface sediments of the Northern and Middle Adriatic shelf were studied during five cruises, from 1977 to 1990, in order to map the distribution of Ca and Mg carbonates in bottom sediments of the Adriatic Sea. The aim of this work was to trace the preferential depositional areas of sediments derived from Italian rivers by distinguishing among the contributions from northeastern Italian rivers, the Po and Apenninic streams. The pattern distribution of dolomite concentration proved to be a good tracer of the alongshore transport of particulate material from the Northern toward the Middle and Southern Adriatic. Moreover, dolomite and textural sedimentary parameters such as grain size distributions discriminate between local, recent sources, and regional, older sources of bottom sedimentary material. The analysis of the main pathways of sediment transfer between different shelf compartments shows that a huge amount of material is transferred from north to south. This occurs in two main shelf sectors: along the Romagna coast, sediments moving inside the belt delimited by the 20 m isobaths are influenced by the local river input and minor coastal gyres, whereas offshore sediments, coming from the northern Adriatic Sea, are transported southward by the Northern Adriatic Coastal Current (NACC); along the Marche and Abruzzo coasts, the "local" belt extends offshore on the outer shelf. In order to obtain a quantitative estimate of sediment accumulation of fine sediments of Northern Adriatic origin along the shelf sectors, a mass budget was calculated for bulk sediments and for dolomite contributions. The budget shows that the amount of sediment transferred between adjacent boxes is always of the order of 50% of the fluvial input to the sea.

  7. A high resolution Adriatic-Ionian Sea circulation model for operational forecasting

    NASA Astrophysics Data System (ADS)

    Ciliberti, Stefania Angela; Pinardi, Nadia; Coppini, Giovanni; Oddo, Paolo; Vukicevic, Tomislava; Lecci, Rita; Verri, Giorgia; Kumkar, Yogesh; Creti', Sergio

    2015-04-01

    A new numerical regional ocean model for the Italian Seas, with focus on the Adriatic-Ionian basin, has been implemented within the framework of Technologies for Situational Sea Awareness (TESSA) Project. The Adriatic-Ionian regional model (AIREG) represents the core of the new Adriatic-Ionian Forecasting System (AIFS), maintained operational by CMCC since November 2014. The spatial domain covers the Adriatic and the Ionian Seas, extending eastward until the Peloponnesus until the Libyan coasts; it includes also the Tyrrhenian Sea and extends westward, including the Ligurian Sea, the Sardinia Sea and part of the Algerian basin. The model is based on the NEMO-OPA (Nucleus for European Modeling of the Ocean - Ocean PArallelise), version 3.4 (Madec et al. 2008). NEMO has been implemented for AIREG at 1/45° resolution model in horizontal using 121 vertical levels with partial steps. It solves the primitive equations using the time-splitting technique for solving explicitly the external gravity waves. The model is forced by momentum, water and heat fluxes interactively computed by bulk formulae using the 6h-0.25° horizontal-resolution operational analysis and forecast fields from the European Centre for Medium-Range Weather Forecast (ECMWF) (Tonani et al. 2008, Oddo et al. 2009). The atmospheric pressure effect is included as surface forcing for the model hydrodynamics. The evaporation is derived from the latent heat flux, while the precipitation is provided by the Climate Prediction Centre Merged Analysis of Precipitation (CMAP) data. Concerning the runoff contribution, the model considers the estimate of the inflow discharge of 75 rivers that flow into the Adriatic-Ionian basin, collected by using monthly means datasets. Because of its importance as freshwater input in the Adriatic basin, the Po River contribution is provided using daily average observations from ARPA Emilia Romagna observational network. AIREG is one-way nested into the Mediterranean Forecasting

  8. Paleohydrology reconstruction and Holocene climate variability in the South Adriatic Sea

    NASA Astrophysics Data System (ADS)

    Siani, G.; Magny, M.; Paterne, M.; Debret, M.; Fontugne, M.

    2012-09-01

    Holocene paleohydrology reconstruction was derived combining planktic and benthic stable oxygen and carbon isotopes, sea surface temperatures (SSTs) and oxygen isotope composition of seawater (δ18Ow) from a high sedimentation core collected in the south Adriatic sea (SAS). Chronology of core is based on 10 AMS 14C measures on planktic foraminifera and tephra markers. Results reveal two contrasted paleohydrological periods that reflect (i) a marked lowering of δ 18Ow/salinity during the early to middle Holocene (11.5 ka to 6.3 ka), including the two-steps sapropel S1 deposition, followed during the middle to upper Holocene by (ii) a prevailed period of increased salinity and enhanced arid conditions in the south Adriatic basin. Superimposed on these trends, short-term centennial-scale hydrological events punctuated the Holocene period in the SAS. During the Early to Middle Holocene, a short-term SST cooling together with a prominent δ 18Ow/salinity lowering, more pronounced than during the sapropel S1 phase, delineates the sapropel S1 interruption. This short interval, coeval to the 8.2 ka event, is also distinguished by a resumption of deep-water convection in the SAS as indicated by stable isotope reconstruction on benthic forminifera. After 6 ka, centennial-scale δ18Ow and G. bulloides δ13C lowering, mostly centered between 3 to 0.6 ka, reflect short term hydrological changes related to a more intensive Po river runoff. These short-term events, even of lesser amplitude compared to the early to middle Holocene period, may have induced a lowering of sea surface density and consequently reduced and/or inhibited the formation of deep bottom waters in the SAS. Comparison of the emerging centennial to millennial-scale hydrological record with previous climatic records from the central Mediterranean area and north of the Alps revealed possible synchronicities (within the radiocarbon-dating uncertainty) between phases of lower salinity in SAS and periods of wetter

  9. Paleohydrology reconstruction and Holocene climate variability in the South Adriatic Sea

    NASA Astrophysics Data System (ADS)

    Siani, G.; Magny, M.; Paterne, M.; Debret, M.; Fontugne, M.

    2013-02-01

    Holocene paleohydrology reconstruction is derived combining planktonic and benthic stable oxygen and carbon isotopes, sea surface temperatures (SSTs) and oxygen isotope composition of seawater (δ18Ow) from a high sedimentation core collected in the South Adriatic Sea (SAS). Core chronology is based on 10 AMS 14C measures on planktonic foraminifera and tephra layers. Results reveal two contrasted paleohydrological periods that reflect (i) a marked lowering of δ18Ow/salinity during the early to mid-Holocene (11.5 ka to 6.3 ka), including the two-step sapropel S1 deposition, followed during the mid- to upper Holocene by (ii) a prevailing period of increased salinity and enhanced arid conditions in the South Adriatic Basin. Superimposed on these trends, short-term centennial-scale hydrological events punctuated the Holocene period in the SAS. During the early to mid-Holocene, two main SST coolings together with prominent δ18Ow/salinity lowering delineate the sapropel S1 interruption and the post-sapropel phase between 7.3 to 6.3 ka. After 6 ka, centennial-scale δ18Ow and G. bulloides δ13C lowering, mostly centered between 3 to 0.6 ka, reflect short-term hydrological changes related to more intensive runoff of the Po and/or Apennine rivers. These short-term events, even of lesser amplitude compared to the early to mid-Holocene period, may have induced a lowering of sea surface density and consequently reduced and/or inhibited the formation of deep bottom waters in the SAS. Comparison of the emerging centennial- to millennial-scale hydrological record with previous climatic records from the central Mediterranean area and north of the Alps reveal possible synchronicities (within the radiocarbon-dating uncertainty) between phases of lower salinity in the SAS and periods of wetter climatic conditions around the north-central Adriatic Sea. Finally, wavelet analyses provide new clues about the potential origin of climate variability in the SAS, confirming the evidence

  10. The role of local and external factors in determining the interannual sea level variability of the Adriatic and Black Seas during the 20th century.

    NASA Astrophysics Data System (ADS)

    Scarascia, Luca; Lionello, Piero

    2016-04-01

    The Adriatic Sea and the Black Sea are two semienclosed basins connected to the Mediterranean Sea by the Otranto and the Bosporus straits, respectively. This work aims to reconstruction the sea level for both basins in the 20th century and to investigate main sources of interannual variability. Using 7 tide gauge timeseries located along the Adriatic coast and 5 along the Black Sea coast, provided by the PSMSL (Permanent service of mean sea level), a seamless sea level timeseries (1900-2009) has been obtained for each basin on the basis of statistical procedure involving PCA and Least Square Method. The comparison with satellite data in the period 1993 - 2009 confirms that these are reliable representations of the observed sea level for the whole basin, showing a great agreement with a correlation value of 0.87 and 0.72 for Adriatic and Black Sea respectively. The sea level has been decomposed in various contributions in order to analyze the role of the factors responsible for its interannual variability. The annual cycles of the local effect of pressure (inverse barometer effect IB), of the steric effect due to temperature and salinity variation and of the wind effect have been computed. The largest contribute for the Adriatic Sea is due to the wind, whilst inverse barometer effect plays a minor role and the steric effect seems to be almost negligible. For the Black Sea, on the contrary, wind effect is negligible, and the largest source of variability is due to the Danube river, which is estimated from the available discharge data of Sulina (one of the exits of the Danube delta. Steric and IB effects play both a minor role in this basin. A linear regression model, built considering as predictor the SLP gradient identified at large scale after having carried out the correlation analysis, is capable to explain a further percentage of variability (about 20-25%) of the sea level after subtracting all the factors considered above. Finally, residual sea levels show a

  11. Paranthias furcifer (Perciformes: Serranidae), a new alien fish in the Mediterranean Sea.

    PubMed

    Dulčić, J; Dragičević, B

    2013-01-01

    A specimen of a creole fish Paranthias furcifer (285 mm total length) was captured in Marina Bay (Croatian coast) in the eastern Adriatic Sea. This is the first Mediterranean record of this species. The possible modes of introduction of species are discussed. PMID:23331154

  12. Pleistocene ice caps on the coastal mountains of the Adriatic Sea

    NASA Astrophysics Data System (ADS)

    Hughes, P. D.; Woodward, J. C.; van Calsteren, P. C.; Thomas, L. E.; Adamson, K. R.

    2010-12-01

    Ice caps once covered large areas of Mount Orjen (1894 m), on the Adriatic coast of Montenegro/Bosnia Herzegovina/Croatia. The largest ice cap covered an area of c. 165 km 2 and reached a maximum ice thickness of c. 450 m, in some areas reaching down to 500 m above modern sea level. U-series dating of secondary carbonates within moraines indicates that the most extensive glaciation occurred during the Middle Pleistocene, correlating with a major phase of glaciation in Greece to the south during MIS 12 (c. 480-430 ka). Later, less extensive, glaciations are also recorded in the cirques and valleys and correlate with glaciations during MIS 6 (190-130 ka) and MIS 5d-2 (110-11.7 ka). Each phase of glaciation would have required large amounts of snow accumulation. Under modern precipitation values, which at c. 5000 mm are some of the highest in Europe, mean annual temperatures would need to be only c. 5-6 °C lower in order to form similar sized glaciers today. A mean annual temperature depression of 12-13 °C would still require >1000 mm of snow accumulation (water equivalent) to balance ablation, suggesting sustained moisture supply during Pleistocene cold stages. Such sustained precipitation supply during Pleistocene cold stages is likely to have been facilitated by major temperature contrasts between the European landmass and the Mediterranean Sea, which are likely to have sustained lee-side vortices to the south of the Alps, in the Gulf of Genoa and Adriatic Sea, forming weak moisture-bearing depressions which tracked across the eastern Adriatic coastal mountains. Large ice caps on the Dinaric Alps would have blocked the inland penetration of these depressions, resulting in much drier conditions in the Balkan interior, creating favourable conditions for the deposition of thick accumulations of loess. The last glaciers on Orjen formed during the Younger Dryas (12.9-11.7 ka) and confirm the influence of North Atlantic Ocean circulation on Pleistocene climate change

  13. Evaluation of genetic diversity and root traits of sea beet accessions of the Adriatic Sea coast

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Thirty nine sea beet [Beta vulgaris L. subsp. maritima (L.) Arcang.] accessions of the Adriatic coast were screened genetically and for their adaptive morpho-functional root traits in order to identify new sources of abiotic resistances for sugar beet breeding programs. Genetic diversity was evaluat...

  14. A nonstationary analysis for the Northern Adriatic extreme sea levels

    NASA Astrophysics Data System (ADS)

    Masina, Marinella; Lamberti, Alberto

    2013-09-01

    The historical data from the Trieste, Venice, Porto Corsini, and Rimini tide gauges have been used to investigate the spatial and temporal changes in extreme high water levels in the Northern Adriatic. A detailed analysis of annual mean sea level evolution at the three longest operating stations shows a coherent behavior both on a regional and global scale. A slight increase in magnitude of extreme water elevations, after the removal of the regularized annual mean sea level necessary to eliminate the effect of local subsidence and sea level rise, is found at the Venice and Porto Corsini stations. It seems to be mainly associated with a wind regime change occurred in the 1990s, due to an intensification of Bora wind events after their decrease in frequency and intensity during the second half of the 20th century. The extreme values, adjusted for the annual mean sea level trend, are modeled using a time-dependent GEV distribution. The inclusion of seasonality in the GEV parameters considerably improves the data fitting. The interannual fluctuations of the detrended monthly maxima exhibit a significant correlation with the variability of the large-scale atmospheric circulation represented by the North Atlantic Oscillation and Arctic Oscillation indices. The different coast exposure to the Bora and Sirocco winds and their seasonal character explain the various seasonal patterns of extreme sea levels observed at the tide gauges considered in the present analysis.

  15. Numerical modelling of sediment transport in the Adriatic Sea

    NASA Astrophysics Data System (ADS)

    Guarnieri, A.; Souza, A. J.; Pinardi, N.; Traykovski, P.

    2014-06-01

    A new sediment transport model, considering currents, tides and waves is presented for the Adriatic Sea basin. The simulations concentrate on the winter of 2002-2003 because of field data availability and interesting intermittent processes occurrence. A process oriented analysis is performed to investigate the impact that Sirocco and Bora wind regimes have on sediment transport. The comparisons of the simulations with the observed data show that the model is capable to capture the main dynamics of sediment transport along the Italian coasts and the sediment concentration within the water column. This latter can reach values up to several g L-1, especially within the first centimetres above the bottom. The sediments are transported mainly southwards along the Italian coasts, consistently with the known literature results, except during Sirocco wind events, which can be responsible for reversing the coastal circulation in the northern area of the basin, and consequently the sediment transport. The resuspension of sediments is also related to the specific wave regimes induced by Bora and Sirocco, the former inducing resuspension events near the coasts while the latter causing a more diffused resuspension regime in the Northern Adriatic basin. Beside the realistic representation of short timescales resuspension/deposition events due to storms, the model was also used to investigate persistent erosion or deposition areas in the Adriatic Sea. Two main depocenters were identified: one, very pronounced, in the surroundings of the Po river delta, and another one a few kilometres off the coast in front of the Ancona promontory. A third region of accumulation, even if less intense, was found to be offshore the southernmost limit of the Gargano region. On the contrary the whole western coast within a distance of a few kilometres from the shore was found to be subject to prevailing erosion. The comparison with observed accumulation and erosion data shows that the model captures

  16. Operational ocean models in the Adriatic Sea: a skill assessment

    NASA Astrophysics Data System (ADS)

    Chiggiato, J.; Oddo, P.

    2006-12-01

    In the framework of the Mediterranean Forecasting System project (MFS) sub-regional and regional numerical ocean forecasting systems performance are assessed by mean of model-model and model-data comparison. Three different operational systems have been considered in this study: the Adriatic REGional Model (AREG); the AdriaROMS and the Mediterranean Forecasting System general circulation model (MFS model). AREG and AdriaROMS are regional implementations (with some dedicated variations) of POM (Blumberg and Mellor, 1987) and ROMS (Shchepetkin and McWilliams, 2005) respectively, while MFS model is based on OPA (Madec et al., 1998) code. The assessment has been done by means of standard scores. The data used for operational systems assessment derive from in-situ and remote sensing measurements. In particular a set of CTDs covering the whole western Adriatic, collected in January 2006, one year of SST from space born sensors and six months of buoy data. This allowed to have a full three-dimensional picture of the operational forecasting systems quality during January 2006 and some preliminary considerations on the temporal fluctuation of scores estimated on surface (or near surface) quantities between summer 2005 and summer 2006. In general, the regional models are found to be colder and fresher than observations. They eventually outperform the large scale model in the shallowest locations, as expected. Results on amplitude and phase errors are also much better in locations shallower than 50 m, while degraded in deeper locations, where the models tend to have a higher homogeneity along the vertical column compared to observations. In a basin-wide overview, the two regional models show some dissimilarities in the local displacement of errors, something suggested by the full three-dimensional picture depicted using CTDs, but also confirmed by the comparison with SSTs. In locations where the regional models are mutually correlated, the aggregated mean-square-error has

  17. On the analysis of an extreme Bora wind event over the northern Adriatic Sea

    NASA Astrophysics Data System (ADS)

    Colucci, R. R.; Pucillo, A.

    2010-09-01

    On 10th March 2010 a severe Bora wind event affected the Friuli Venezia Giulia region, northeastern Italy, in particular the gulf of Trieste area (northern Adriatic Sea). Such event has been driven by a widespread westward moving cold pool aloft, coming from the Western Asia, that brought an intense potential vorticity anomaly over the western Mediterranean Sea. It determined a deep cyclogenesis involving all the troposphere. The pressure gradient force in the lowest layers forced a northeastern wind to blow with noticeable strength over the gulf of Trieste area and the Karstic region. The mean ground wind velocity has reached values above 27 m/s (about 100 km/h) for several hours, and maximum gusts exceeded 42 m/s (about 150 km/h) over Trieste town. The northeastern sector of the Adriatic Sea is frequently affected by strong Bora events in particular during the winter semester. This is a characteristic local wind mostly influenced by the orography of the Karstic relieves to the east of Trieste town. The target of this work is to assess the climatological relevance of such an event by comparing it with the most representative events of the past. It has been possible thanks to the long term archive of meteorological observations in Trieste site (I.R. Accademia di Commercio e Nautica, Regio Comitato Talassografico Italiano, Ministero dell'Agricoltura e Foreste, Consiglio Nazionale delle Ricerche): we have found out that this is one of the ten strongest Bora event along the 1871-2010 period. Considerations about the trend and frequency of severe Bora events have been proposed.

  18. Towards a coastal ocean forecasting system in Southern Adriatic Northern Ionian seas based on unstructured-grid model

    NASA Astrophysics Data System (ADS)

    Federico, Ivan; Oddo, Paolo; Pinardi, Nadia; Coppini, Giovanni

    2014-05-01

    The Southern Adriatic Northern Ionian Forecasting System (SANIFS) operational chain is based on a nesting approach. The large scale model for the entire Mediterranean basin (MFS, Mediterranean Forecasting system, operated by INGV, e.g. Tonani et al. 2008, Oddo et al. 2009) provides lateral open boundary conditions to the regional model for Adriatic and Ionian seas (AIFS, Adriatic Ionian Forecasting System) which provides the open-sea fields (initial conditions and lateral open boundary conditions) to SANIFS. The latter, here presented, is a coastal ocean model based on SHYFEM (Shallow HYdrodynamics Finite Element Model) code, which is an unstructured grid, finite element three-dimensional hydrodynamic model (e.g. Umgiesser et al., 2004, Ferrarin et al., 2013). The SANIFS hydrodynamic model component has been designed to provide accurate information of hydrodynamics and active tracer fields in the coastal waters of Southern Eastern Italy (Apulia, Basilicata and Calabria regions), where the model is characterized by a resolution of about of 200-500 m. The horizontal resolution is also accurate in open-sea areas, where the elements size is approximately 3 km. During the development phase the model has been initialized and forced at the lateral open boundaries through a full nesting strategy directly with the MFS fields. The heat fluxes has been computed by bulk formulae using as input data the operational analyses of European Centre for Medium-Range Weather Forecasts. Short range pre-operational forecast tests have been performed in different seasons to evaluate the robustness of the implemented model in different oceanographic conditions. Model results are validated by means of comparison with MFS operational results and observations. The model is able to reproduce the large-scale oceanographic structures of the area (keeping similar structures of MFS in open sea), while in the coastal area significant improvements in terms of reproduced structures and dynamics are

  19. Mass Mortality Events in the NW Adriatic Sea: Phase Shift from Slow- to Fast-Growing Organisms

    PubMed Central

    Di Camillo, Cristina Gioia; Cerrano, Carlo

    2015-01-01

    Massive outbreaks are increasing all over the world, which are likely related to climate change. The North Adriatic Sea, a sub-basin of the Mediterranean Sea, is a shallow semi-closed sea receiving high nutrients inputs from important rivers. These inputs sustain the highest productive basin of the Mediterranean Sea. Moreover, this area shows a high number of endemisms probably due to the high diversity of environmental conditions and the conspicuous food availability. Here, we documented two massive mortalities (2009 and 2011) and the pattern of recovery of the affected biocoenoses in the next two years. Results show an impressive and fast shift of the benthic assemblage from a biocoenosis mainly composed of slow-growing and long-lived species to a biocoenosis dominated by fast-growing and short-lived species. The sponge Chondrosia reniformis, one of the key species of this assemblage, which had never been involved in previous massive mortality events in the Mediterranean Sea, reduced its coverage by 70%, and only few small specimens survived. All the damaged sponges, together with many associated organisms, were detached by rough-sea conditions, leaving large bare areas on the rocky wall. Almost three years after the disease, the survived specimens of C. reniformis did not increase significantly in size, while the bare areas were colonized by fast-growing species such as stoloniferans, hydrozoans, mussels, algae, serpulids and bryozoans. Cnidarians were more resilient than massive sponges since they quickly recovered in less than one month. In the study area, the last two outbreaks caused a reduction in the filtration efficiency of the local benthic assemblage by over 60%. The analysis of the times series of wave heights and temperature revealed that the conditions in summer 2011 were not so extreme as to justify severe mass mortality, suggesting the occurrence of other factors which triggered the disease. The long-term observations of a benthic assemblage in the

  20. Mass Mortality Events in the NW Adriatic Sea: Phase Shift from Slow- to Fast-Growing Organisms.

    PubMed

    Di Camillo, Cristina Gioia; Cerrano, Carlo

    2015-01-01

    Massive outbreaks are increasing all over the world, which are likely related to climate change. The North Adriatic Sea, a sub-basin of the Mediterranean Sea, is a shallow semi-closed sea receiving high nutrients inputs from important rivers. These inputs sustain the highest productive basin of the Mediterranean Sea. Moreover, this area shows a high number of endemisms probably due to the high diversity of environmental conditions and the conspicuous food availability. Here, we documented two massive mortalities (2009 and 2011) and the pattern of recovery of the affected biocoenoses in the next two years. Results show an impressive and fast shift of the benthic assemblage from a biocoenosis mainly composed of slow-growing and long-lived species to a biocoenosis dominated by fast-growing and short-lived species. The sponge Chondrosia reniformis, one of the key species of this assemblage, which had never been involved in previous massive mortality events in the Mediterranean Sea, reduced its coverage by 70%, and only few small specimens survived. All the damaged sponges, together with many associated organisms, were detached by rough-sea conditions, leaving large bare areas on the rocky wall. Almost three years after the disease, the survived specimens of C. reniformis did not increase significantly in size, while the bare areas were colonized by fast-growing species such as stoloniferans, hydrozoans, mussels, algae, serpulids and bryozoans. Cnidarians were more resilient than massive sponges since they quickly recovered in less than one month. In the study area, the last two outbreaks caused a reduction in the filtration efficiency of the local benthic assemblage by over 60%. The analysis of the times series of wave heights and temperature revealed that the conditions in summer 2011 were not so extreme as to justify severe mass mortality, suggesting the occurrence of other factors which triggered the disease. The long-term observations of a benthic assemblage in the

  1. Investigation of model capability in capturing vertical coastal processes: A case study in the Adriatic Sea

    NASA Astrophysics Data System (ADS)

    McKiver, William; Sannino, Gianmaria; Bellafiore, Debora

    2015-04-01

    Coastal horizontal and vertical processes play an important role in ocean dynamics. Being the interface between land and sea, they are strongly influenced by winds, river inputs, tides, heat and water fluxes, topographic features, as well as human activities. In this work we perform a set of simulations using two different models, SHYFEM and MITgcm, each employing very different numerical approaches (finite elements and finite volume respectively). This allows us to access their capability to capture a number of coastal processes, specifically considering the role of upwelling and downwelling in the Northern Adriatic Sea. We focus on the Adriatic as its topography, having a very shallow northern basin becoming deeper towards the south, as well as the local atmospheric conditions and its large number of freshwater sources (about a third of the entire Mediterranean), make it prone to dense water events, when cold north-easterly winter winds induce dense water formation in the shallow northern coastal shelf. These extreme dense water events have many complex influences and thus are particularly challenging to understand and model, though their impact on the wider ocean circulation has made them an important topic of research. In this study we focus on one particularly strong dense water formation event that occurred in the beginning of 2012. This serves as an interesting test case to assess both the models strengths and weaknesses, while giving an opportunity to understand how these events affect coastal upwelling and downwelling processes. Using the two very different models we examine the impact of different resolutions (horizontal and vertical), different preconditionings as well as assessing the importance of non-hydrostatic dynamics, in order to identify the crucial model characteristics needed to best reproduce coastal processes.

  2. Seasonal and interannual dynamics of microzooplankton abundances in the Gulf of Trieste (Northern Adriatic Sea, Italy)

    NASA Astrophysics Data System (ADS)

    Monti, Marina; Minocci, Marco; Milani, Luisella; Fonda Umani, Serena

    2012-12-01

    Abundance and composition of microzooplankton were studied over a 15 years period (from March 1986 to December 1990 and from July 1998 to December 2010) in the Gulf of Trieste (Adriatic Sea, NE Mediterranean Sea). Sampling was conducted biweekly-monthly at the surface at the historical station C1, 200 m offshore (bottom depth 17.5 m). Aloricate ciliates dominated in both periods (median 117 and 243 ind. L-1 in the first and second period respectively) while tintinnids were more abundant in the first period (median 55 ind. L-1vs 16 ind. L-1). For heterotrophic dinoflagellates there are no data during the first period and in the second one they represented the second major group. Micrometazoans remained almost constant over time. In the first period all microzooplankton groups showed a maximum in April, while in the last period the peak has shifted to September. This is particularly evident for both aloricate ciliates and micrometazoans. Tintinnids, that in the past had the absolute maximum in spring, in the second period maintained the only, lower peak in October. Tintinnids in the first period were constituted by 27 species and dominated by the genera Tintinnopsis, Stenosemella and Salpingella. In the last 10 years we registered a dramatic decrease in abundance, paralleling an increase in species (40) with some "new entries" as well as the almost complete disappearance of genera Helicostomella, Favella, Coxiella and Steenstrupiella. The observed changes of the seasonal dynamics of microzooplankton abundance, as well as of the tintinnids composition over the long period considered in our study, might suggest a climatic forcing together with the known anthropogenic oligotrophication of the entire North Adriatic.

  3. Nematofauna in the Adriatic Sea: review and check-list of free-living nematode species

    NASA Astrophysics Data System (ADS)

    Travizi, Ana; Vidaković, Jasna

    1998-02-01

    The present paper presents a collection and synthesis of data found in numerous publications on Adriatic Sea nematofauna, as well as unpublished, data mentioned in annotations. For this purpose, a chronological order of investigations and a general survey of the species that occurred in the Adriatic Sea are given. In all, 281 free-living nematode species comprised in 133 genera and 34 families were discerned and listed in a taxonomic review, according to their spatial distribution. In special cases, descriptions of habitat features were noted. The position of species characterized by high population densities, their importance, and contribution to the faunistic composition of certain parts of the Adriatic were also discussed. The summary of the results, of prevailing research on free-living marine nematodes serves as a tool for making distinctions concerning the research level and state of nematofauna knowledge in different parts of the Adriatic Sea. Northern Adriatic nematofauna has been considerably more intensively investigated than that of the Central and South Adriatic.

  4. Natural radionuclides in seafood from the central Adriatic Sea (Italy).

    PubMed

    Desideri, D; Meli, M A; Roselli, C

    2011-02-01

    Activity concentrations of ²¹⁰Po, ²¹⁰Pb, and ⁴⁰K were measured in different samples of marine organisms from the central Adriatic Sea. The marine organisms were purchased from the local consumer market during all four seasons of the year to evaluate the spatial and temporal distribution of the natural radioactivity. The concentration trend is the following: ⁴⁰K > ²¹⁰Po > ²¹⁰Pb. ⁴⁰K concentration ranged between 54.9 and 235.9 Bq kg⁻¹ fresh weight, and the arithmetic mean of Pb concentration for all samples is <0.7 Bq kg⁻¹ fresh weight. Po activity concentration ranged between 0.3 and 44.6 Bq kg⁻¹ fresh weight; its arithmetic mean was 5.7 ± 7.2 Bq kg⁻¹ fresh weight. Among the pelagic species, anchovy displayed the highest polonium concentration. The data obtained depend upon the type of marine organism and the period of sampling. Committed effective dose due to ²¹⁰Po ingestion from marine food for individuals in the two different population groups was calculated to be 95.9 and 466.4 μSv y⁻¹, respectively. PMID:21399431

  5. Hydromorphic to subaqueous soils transitions in the central Grado lagoon (Northern Adriatic Sea, Italy)

    NASA Astrophysics Data System (ADS)

    Vittori Antisari, Livia; De Nobili, Maria; Ferronato, Chiara; Natale, Marco; Pellegrini, Elisa; Vianello, Gilmo

    2016-05-01

    The Grado lagoon is among the largest in the Mediterranean sea and is characterized by salt marshes, where tides influenced the development of a complex micromorphology coupled to a micromosaic of vegetation covers. This study represents the first contribution to the understanding of the main processes governing formation, development and spatial transitions between hydromorphic and subaqueous soils in an Adriatic lagoon ecosystem. Physicochemical characteristics and development of soils were investigated in three salt marshes differing for their proximity to the open sea, textural composition and age of formation. Soils of back barrier salt marshes had A/C profiles and were mostly characterized by a sandy coarse texture that allows rapid drainage and subsurface oxygen exchanges. Soil sequences from the inner salt marsh to its submerged border slope or to a brackish waterhole do not simply represent a hydrosequence, but also reflect erosion/sorting/accumulation processes. The soils in the central part of the lagoon have finer texture and in displayed transition or cambic horizons. Silty clay loam textures and low positions allowed the development of more severe anoxic conditions and accumulation of sulphides. The tide oscillation strongly contributed to formation of redoximorphic features, intensity of anaerobic conditions but also colonization by different plant communities. Discriminant analysis was performed to identify physicochemical properties which discriminate the different soils according to geo-morphological position and prevailing plants. It confirmed that differentiation of plant communities occurred according to distinct morphological and physicochemical soil properties, but also acted as a primary affecting factor of pedogenesis.

  6. The Clodia database: a long time series of fishery data from the Adriatic Sea

    PubMed Central

    Mazzoldi, Carlotta; Sambo, Andrea; Riginella, Emilio

    2014-01-01

    Long-term time series of species abundances can depict population declines and changes in communities in response to anthropogenic activities, climate changes, alterations of trophic relationships. Here we present a database of historical marine fishery landing data, covering a remarkably long time series (1945–2013) and referring to one of the most exploited areas of the Mediterranean Sea, the Adriatic Sea. The database includes two time series of landing data, 1945–2013 and 1997–2013, from the official statistics of the fish market of Chioggia, where the major fishing fleet of the area operates. Comparisons between the landing data of the database and landing data from other fisheries or data from scientific surveys support the reliability of the time series in depicting changes in species abundances. The database is expected to be used by fishery biologists and ecologists interested in depicting and understanding temporal variations in species abundances and community composition, in relation to environmental and anthropogenic factors. PMID:25977775

  7. Estimation of the Adriatic Sea water turnover time using fallout 90Sr as a radioactive tracer

    NASA Astrophysics Data System (ADS)

    Franić, Zdenko

    2005-08-01

    Systematic, long-term measurements, starting in 1963, of 90Sr activity concentrations in sea water have been performed at four locations (cities of Rovinj, Rijeka, Split and Dubrovnik) along the Croatian coast of the Adriatic Sea. In addition, fallout samples were collected in the city of Zadar. 90Sr activity concentrations are in good correlation with the fallout activity, the coefficient of correlation being 0.72. After the nuclear moratorium on atmospheric nuclear bomb tests in 1960s, 90Sr activity concentrations in sea water exponentially dropped from 14.8 ± 2.4 Bq m -3 in 1963 to 2.0 ± 0.3 Bq m -3 in 2003. In the same period, the total annual 90Sr land surface deposit in Zadar fell by three orders of magnitude, from 713.3 Bq m -2 in 1963 to 0.4 Bq m -2 in 2003. Using strontium sea water and fallout data, a mathematical model was developed to describe the rate of change of 90Sr activity concentrations in the Adriatic Sea water and estimate its mean residence time in the Adriatic. By fitting the experimental data to a theoretically predicted curve, the mean residence time of 90Sr in the Adriatic Sea water was estimated to be approximately 3.4 ± 0.4 years, standard deviation being calculated by Monte Carlo simulations. As in physical oceanography 90Sr can be used as effective radioactive tracer of water mass transport, this value also reflects the upper limit for turnover time of the Adriatic Sea water. The turnover time of 3.4 years for the Adriatic Sea water is in reasonable agreement with the value which was estimated, by studying water flows through the Strait of Otranto, to be on the order of 1 year.

  8. Unstructured-grid coastal ocean modelling in Southern Adriatic and Northern Ionian Seas

    NASA Astrophysics Data System (ADS)

    Federico, Ivan; Pinardi, Nadia; Coppini, Giovanni; Oddo, Paolo

    2016-04-01

    The Southern Adriatic Northern Ionian coastal Forecasting System (SANIFS) is a short-term forecasting system based on unstructured grid approach. The model component is built on SHYFEM finite element three-dimensional hydrodynamic model. The operational chain exploits a downscaling approach starting from the Mediterranean oceanographic-scale model MFS (Mediterranean Forecasting System, operated by INGV). The implementation set-up has been designed to provide accurate hydrodynamics and active tracer processes in the coastal waters of Southern Eastern Italy (Apulia, Basilicata and Calabria regions), where the model is characterized by a variable resolution in range of 50-500 m. The horizontal resolution is also high in open-sea areas, where the elements size is approximately 3 km. The model is forced: (i) at the lateral open boundaries through a full nesting strategy directly with the MFS (temperature, salinity, non-tidal sea surface height and currents) and OTPS (tidal forcing) fields; (ii) at surface through two alternative atmospheric forcing datasets (ECMWF and COSMOME) via MFS-bulk-formulae. Given that the coastal fields are driven by a combination of both local/coastal and deep ocean forcings propagating along the shelf, the performance of SANIFS was verified first (i) at the large and shelf-coastal scales by comparing with a large scale CTD survey and then (ii) at the coastal-harbour scale by comparison with CTD, ADCP and tide gauge data. Sensitivity tests were performed on initialization conditions (mainly focused on spin-up procedures) and on surface boundary conditions by assessing the reliability of two alternative datasets at different horizontal resolution (12.5 and 7 km). The present work highlights how downscaling could improve the simulation of the flow field going from typical open-ocean scales of the order of several km to the coastal (and harbour) scales of tens to hundreds of meters.

  9. Consumption rates and prey preference of the invasive gastropod Rapana venosa in the Northern Adriatic Sea

    NASA Astrophysics Data System (ADS)

    Savini, Dario; Occhipinti-Ambrogi, Anna

    2006-05-01

    The alien Asian gastropod Rapana venosa (Valenciennes 1846) was first recorded in 1973 along the Italian coast of the Northern Adriatic Sea. Recently, this predator of bivalves has been spreading all around the world oceans, probably helped by ship traffic and aquaculture trade. A caging experiment in natural environment was performed during the summer of 2002 in Cesenatico (Emilia-Romagna, Italy) in order to estimate consumption rates and prey preference of R. venosa. The prey items chosen were the Mediterranean mussel Mytilus galloprovincialis (Lamarck 1819), the introduced carpet clam Tapes philippinarum (Adams and Reeve 1850), both supporting the local fisheries, and the Indo-Pacific invasive clam Anadara (Scapharca) inaequivalvis (Bruguière 1789). Results showed an average consumption of about 1 bivalve prey per day (or 1.2 g wet weight per day). Predation was species and size selective towards small specimens of A. inaequivalvis; consumption of the two commercial species was lower. These results might reduce the concern about the economical impact on the local bivalve fishery due to the presence of the predatory gastropod. On the other hand, selective predation might probably alter local community structure, influencing competition amongst filter feeder/suspension feeder bivalve species and causing long-term ecological impact. The large availability of food resource and the habitat characteristics of the Emilia-Romagna littoral makes this area an important breeding ground for R. venosa in the Mediterranean Sea, thus worthy of consideration in order to understand the bioinvasion ecology of this species and to control its likely further dispersal.

  10. The Occurrence of Internal Tides along the Italian Coast of the Adriatic Sea

    NASA Astrophysics Data System (ADS)

    Wang, Dong; Pinardi, Nadia; Dobricic, Srdjan; Guarnieri, Antonio; Oddo, Paolo

    2015-04-01

    The occurrence of internal tides along the Italian coast of the Adriatic Sea during stratification season is revealed by a high-resolution, state-of-the-art, three-dimensional primitive-equation baroclinic tidal ocean model of the Adriatic Sea. The NEMO (Nucleus for European Modelling of the Ocean) model is implemented in the Adriatic Sea with a horizontal resolution of 1°/48 and 120 vertical layers. Tidal components important for the Adriatic, including four major semi-diurnal and three major diurnal tides, are simulated by imposing tidal elevations and velocities along the model domain's southern boundary, which is in the northern Ionian Sea. Effects of atmospheric pressure and wind stress are simulated as well. The co-tidal charts of both semi-diurnal and diurnal tides are well reproduced by the model, suggesting that the hydrodynamics key to tidal processes in the Adriatic (Kelvin, Poincare, and topographic waves) are correctly represented. Compared against tide gauge observations, tidal harmonic analysis shows that the averaged error of modelled amplitudes and phases at eight stations along the Italian coast are 15% and 5%, respectively. Vertical oscillations of isotherms near diurnal frequencies are evident at sites along the Italian coast during stratification season. Such oscillations are absent when the tidal forcings are removed from the model. The occurrence of internal tides is readily explained by the supercritical slope theory.

  11. Acidification of the Mediterranean Sea from anthropogenic carbon penetration

    NASA Astrophysics Data System (ADS)

    Hassoun, Abed El Rahman; Gemayel, Elissar; Krasakopoulou, Evangelia; Goyet, Catherine; Abboud-Abi Saab, Marie; Guglielmi, Véronique; Touratier, Franck; Falco, Cédric

    2015-08-01

    This study presents an estimation of the anthropogenic CO2 (CANT) concentrations and acidification (ΔpH=pH2013-pHpre-industrial) in the Mediterranean Sea, based upon hydrographic and carbonate chemistry data collected during the May 2013 MedSeA cruise. The concentrations of CANT were calculated using the composite tracer TrOCA. The CANT distribution shows that the most invaded waters (>60 μmol kg-1) are those of the intermediate and deep layers in the Alboran, Liguro- and Algero-Provencal Sub-basins in the Western basin, and in the Adriatic Sub-basin in the Eastern basin. Whereas the areas containing the lowest CANT concentrations are the deep layers of the Eastern basin, especially those of the Ionian Sub-basin, and those of the northern Tyrrhenian Sub-basin in the Western basin. The acidification level in the Mediterranean Sea reflects the excessive increase of atmospheric CO2 and therefore the invasion of the sea by CANT. This acidification varies between -0.055 and -0.156 pH unit and it indicates that all Mediterranean Sea waters are already acidified, especially those of the Western basin where ΔpH is rarely less than -0.1 pH unit. Both CANT concentrations and acidification levels are closely linked to the presence and history of the different water masses in the intermediate and deep layers of the Mediterranean basins. Despite the high acidification levels, both Mediterranean basins are still highly supersaturated in calcium carbonate minerals.

  12. Ingestion of marine debris by loggerhead sea turtles, Caretta caretta, in the Adriatic Sea.

    PubMed

    Lazar, Bojan; Gračan, Romana

    2011-01-01

    We examined the occurrence of marine debris in the gastrointestinal tract of 54 loggerhead sea turtles (Caretta caretta) found stranded or incidentally captured dead by fisheries in the Adriatic Sea, with a curved carapace length of 25.0-79.2 cm. Marine debris was present in 35.2% of turtles and included soft plastic, ropes, Styrofoam and monofilament lines found in 68.4%, 42.1%, 15.8% and 5.3% of loggerheads that have ingested debris, respectively. The dry mass of debris per turtle was low, ranging from <0.01 to 0.71 g, and the ingestion was not significantly affected by sex or body size (all p>0.05). Marine debris averaged 2.2 ± 8.0% of dry mass of gut content, with a maximum of 35% found in a juvenile turtle that most likely died due to debris ingestion. Considering the relatively high occurrence of debris intake and possible sub-lethal effects of even small quantities of marine debris, this can be an additional factor of concern for loggerheads in the Adriatic Sea. PMID:21036372

  13. Mitochondrial DNA Reveals Genetic Structuring of Pinna nobilis across the Mediterranean Sea

    PubMed Central

    Sanna, Daria; Cossu, Piero; Dedola, Gian Luca; Scarpa, Fabio; Maltagliati, Ferruccio; Castelli, Alberto; Franzoi, Piero; Lai, Tiziana; Cristo, Benedetto; Curini-Galletti, Marco; Francalacci, Paolo; Casu, Marco

    2013-01-01

    Pinna nobilis is the largest endemic Mediterranean marine bivalve. During past centuries, various human activities have promoted the regression of its populations. As a consequence of stringent standards of protection, demographic expansions are currently reported in many sites. The aim of this study was to provide the first large broad-scale insight into the genetic variability of P. nobilis in the area that encompasses the western Mediterranean, Ionian Sea, and Adriatic Sea marine ecoregions. To accomplish this objective twenty-five populations from this area were surveyed using two mitochondrial DNA markers (COI and 16S). Our dataset was then merged with those obtained in other studies for the Aegean and Tunisian populations (eastern Mediterranean), and statistical analyses (Bayesian model-based clustering, median-joining network, AMOVA, mismatch distribution, Tajima’s and Fu’s neutrality tests and Bayesian skyline plots) were performed. The results revealed genetic divergence among three distinguishable areas: (1) western Mediterranean and Ionian Sea; (2) Adriatic Sea; and (3) Aegean Sea and Tunisian coastal areas. From a conservational point of view, populations from the three genetically divergent groups found may be considered as different management units. PMID:23840684

  14. Mitochondrial DNA reveals genetic structuring of Pinna nobilis across the Mediterranean Sea.

    PubMed

    Sanna, Daria; Cossu, Piero; Dedola, Gian Luca; Scarpa, Fabio; Maltagliati, Ferruccio; Castelli, Alberto; Franzoi, Piero; Lai, Tiziana; Cristo, Benedetto; Curini-Galletti, Marco; Francalacci, Paolo; Casu, Marco

    2013-01-01

    Pinna nobilis is the largest endemic Mediterranean marine bivalve. During past centuries, various human activities have promoted the regression of its populations. As a consequence of stringent standards of protection, demographic expansions are currently reported in many sites. The aim of this study was to provide the first large broad-scale insight into the genetic variability of P. nobilis in the area that encompasses the western Mediterranean, Ionian Sea, and Adriatic Sea marine ecoregions. To accomplish this objective twenty-five populations from this area were surveyed using two mitochondrial DNA markers (COI and 16S). Our dataset was then merged with those obtained in other studies for the Aegean and Tunisian populations (eastern Mediterranean), and statistical analyses (Bayesian model-based clustering, median-joining network, AMOVA, mismatch distribution, Tajima's and Fu's neutrality tests and Bayesian skyline plots) were performed. The results revealed genetic divergence among three distinguishable areas: (1) western Mediterranean and Ionian Sea; (2) Adriatic Sea; and (3) Aegean Sea and Tunisian coastal areas. From a conservational point of view, populations from the three genetically divergent groups found may be considered as different management units. PMID:23840684

  15. Long Waves Perturbations to Astronomical Tides in Adriatic and Tyrrenian Sea

    SciTech Connect

    Sigismondi, Costantino

    2008-01-03

    Portable tide gauges have been made with ultrasonic detectors with acquisition rate of 100 data per minute. With them we measured mean sea level variations in different locations of Adriatic and Tyrrenian sea around latitude 42 deg. N. Several long term variations are superimposed to astronomical tide, ranging from 4 to 60 minutes. Their nature of seiches or edge waves and their identification with transversal oscillations of the whole sea are discussed.

  16. Common sole in the northern and central Adriatic Sea: Spatial management scenarios to rebuild the stock

    NASA Astrophysics Data System (ADS)

    Scarcella, Giuseppe; Grati, Fabio; Raicevich, Saša; Russo, Tommaso; Gramolini, Roberto; Scott, Robert D.; Polidori, Piero; Domenichetti, Filippo; Bolognini, Luca; Giovanardi, Otello; Celić, Igor; Sabatini, Laura; Vrgoč, Nedo; Isajlović, Igor; Marčeta, Bojan; Fabi, Gianna

    2014-05-01

    The northern and central Adriatic Sea represents an important spawning and aggregation area for common sole (Solea solea) and provides for around 20% of the Mediterranean landings. In this area, this resource is mainly exploited with rapido trawl and set nets. The stock is not yet depleted and faces a situation of growth overfishing. The comparison between the spatial distribution by age of S. solea and the geographic patterns of the rapido trawl fishing effort evidenced an overlapping of this fishing activity with the area where juveniles concentrate (age groups 0-2). The majority of spawners inhabits specific offshore areas, here defined as ‘sole sanctuaries', where high concentrations of debris and benthic communities make difficult trawling with rapido. The aim of this study was to evaluate existing spatial management regimes and potential new spatial and temporal closures in the northern and central Adriatic Sea using a simple modelling tool. Two spatial simulations were carried out in order to verify the effectiveness of complementary methods for the management of fisheries: the ban of rapido trawling from October to December within 6 nautical miles and 9 nautical miles of the Italian coast. The focus of the simulation is that the effort of the rapido trawl is moved far from the coast during key sole recruitment periods, when the juveniles are moving from the inshore nursery area toward the offshore feeding grounds. The management scenarios showed that a change in selectivity would lead to a clear increase in the spawning stock biomass and an increase in landings of S. solea in the medium-term. The rapido trawl activity could be managed by using a different logic, bearing in mind that catches and incomes would increase with small changes in the spatial pattern of the fishing effort. The present study highlights the importance of taking into account spatial dimensions of fishing fleets and the possible interactions that can occur between fleets and target

  17. Early diagenesis and nutrient benthic fluxes in the Adriatic Sea

    NASA Astrophysics Data System (ADS)

    Spagnoli, F.; Frascari, F.; Marcaccio, M.; Bergamin, M. C.

    2003-04-01

    Early diagenesis processes and dissolved nutrient benthic fluxes of Northern and Central Adriatic Sea bottom sediments were investigate in order to know different sedimentary environmental settings. The study was carried out in 12 stations by means of an integrated analysis of pore water and solid phase composition. In each station one core, about one meter long, was collected. In the solid phase the following parameters were determined: grain size, mineralogy, Fe, Mn, Ca, Mg, Al, S, organic carbon, total nitrogen, total P. In pore waters nitrate, nitrite, ammonia, phosphate, alkalinity, sulphate, Fe, Mn and silica were analysed. Benthic fluxes were measured in situ, by benthic chamber, and calculated by modelisation of pore waters. In each station also the chemical-physical parameters of water column were measured. The area North of the Po River is characterised mainly by carbonate sediments, by low phosphate fluxes towards water column, in some cases even negative, due to authigenic apatite precipitation and by low ammonia fluxes for low reactive organic matter inputs. Near Tagliamento and Adige-Brenta river mouths sediments are higher in organic matter contents in comparison with offshore areas. In these environments pore water nutrient regeneration takes place in the uppermost centimetres of sediment by oxic and suboxic organic matter degradation (Adige-Brenta prodelta sediments) or at higher depth by organic matter degradation, mainly anoxic, via sulphate reduction (Tagliamento prodelta area). Fluxes of phosphate and TCO2 in these two areas are slowly higher than other North Po River areas. The Po River proximal prodelta area is characterised by high ammonia, phosphate and TCO2 fluxes due to high organic matter and silicate inputs, degrading mainly in anoxic conditions by sulphate reduction. When bottom water column reach anoxic conditions in these areas also Fe, Mn and phosphate fluxes increase for dissolution of Fe and Mn oxi-hydroxide surface layer. South

  18. Repeat hydrography in the Mediterranean Sea, data from the Meteor cruise 84/3 in 2011

    NASA Astrophysics Data System (ADS)

    Tanhua, T.; Hainbucher, D.; Cardin, V.; Álvarez, M.; Civitarese, G.

    2013-03-01

    Here we report on data from an oceanographic cruise on the German research vessel Meteor covering large parts of the Mediterranean Sea during spring of 2011. The main objectives of this cruise was to conduct measurements of physical, chemical and biological variables on a section across the Mediterranean Sea with the goal of producing a synoptic picture of the distribution of relevant physical and biogeochemical properties, in order to compare those to historic data sets. During the cruise, a comprehensive data set of relevant variables following the guide lines for repeat hydrography outlined by the GO-SHIP group (http://www.go-ship.org/) was collected. The measurements include; salinity and temperature (CTD), an over-determined carbonate system, inorganic nutrients, oxygen, transient tracers (CFC-12, SF6), Helium isotopes and tritium, and carbon isotopes. The cruise sampled all major basins of the Mediterranean Sea following roughly an east-to-west section from the coast of Lebanon to through the Strait of Gibraltar, and to the coast of Portugal. Also a south-to-north section from the Ionian Sea to the Adriatic Sea was carried out. Additionally, sampling in the Aegean, Adriatic and Tyrrhenian Seas were carried out. The sections roughly followed lines and positions that have been sampled previously during other programs, thus providing the opportunity for comparative investigations of the temporal development of various parameters.

  19. Repeat hydrography in the Mediterranean Sea, data from the Meteor cruise 84/3 in 2011

    NASA Astrophysics Data System (ADS)

    Tanhua, T.; Hainbucher, D.; Cardin, V.; Álvarez, M.; Civitarese, G.; McNichol, A. P.; Key, R. M.

    2013-07-01

    Here we report on data from an oceanographic cruise on the German research vessel Meteor covering large parts of the Mediterranean Sea during spring of 2011. The main objective of this cruise was to conduct measurements of physical, chemical and biological variables on a section across the Mediterranean Sea with the goal of producing a synoptic picture of the distribution of relevant physical and biogeochemical properties, in order to compare those to historic data sets. During the cruise, a comprehensive data set of relevant variables following the guide lines for repeat hydrography outlined by the GO-SHIP group (http://www.go-ship.org/) was collected. The measurements include salinity and temperature (CTD), an over-determined carbonate system, inorganic nutrients, oxygen, transient tracers (CFC-12, SF6), helium isotopes and tritium, and carbon isotopes. The cruise sampled all major basins of the Mediterranean Sea following roughly an east-to-west section from the coast of Lebanon through to the Strait of Gibraltar, and to the coast of Portugal. Also a south-to-north section from the Ionian Sea to the Adriatic Sea was carried out. Additionally, sampling in the Aegean, Adriatic and Tyrrhenian Seas were carried out. The sections roughly followed lines and positions that have been sampled previously during other programs, thus providing the opportunity for comparative investigations of the temporal development of various parameters.

  20. Gene flow, population growth and a novel substitution rate estimate in a subtidal rock specialist, the black-faced blenny Tripterygion delaisi (Perciformes, Blennioidei, Tripterygiidae) from the Adriatic Sea

    PubMed Central

    Koblmüller, Stephan; Steinwender, Bernd; Weiß, Sara; Sefc, Kristina M.

    2015-01-01

    Population histories depend on the interplay between exogeneous and endogeneous factors. In marine species, phylogeographic and demographic patterns are often shaped by sea level fluctuations, water currents and dispersal ability. Using mitochondrial control region sequences (n = 120), we infer phylogeographic structure and historic population size changes of a common littoral fish species, the black-faced blenny Tripterygion delaisi (Perciformes, Blennioidei, Tripterygiidae) from the north-eastern Adriatic Sea. We find that Adriatic T. delaisi are differentiated from conspecific populations in the remaining Mediterranean, but display little phylogeographic structure within the Adriatic basin. The pattern is consistent with passive dispersal of planktonic larvae along cyclonic currents within the Adriatic Sea, but limited active dispersal of adults. Demographic reconstructions are consistent with recent population expansion, probably triggered by rising sea levels after the last glacial maximum (LGM). Placing the onset of population growth between the LGM and the warming of surface waters (18 000–13 000 years BP) and employing a novel expansion dating approach, we inferred a substitution rate of 2.61–3.61% per site per MY. Our study is one of only few existing investigations of the genetic structure of animals within the Adriatic basin and is the first to provide an estimate for mitochondrial control region substitution rates in blennioid fishes. PMID:26617435

  1. Possible observation of horizontal roll vortices over the Adriatic Sea during bora

    NASA Astrophysics Data System (ADS)

    Belusic, Danijel; Vecenaj, Zeljko; LeMone, Margaret

    2015-05-01

    We report a possible occurrence of horizontal roll vortices over the Adriatic Sea during the bora wind. The National Center for Atmospheric Research Electra aircraft measured the turbulence structure above the Adriatic on 07 November 1999 during the Mesoscale Alpine Program. The data indicate that horizontal roll vortices are generated by the strong cold-air outbreak associated with bora. The rolls have a horizontal wavelength of about 1 km and an aspect ratio of approximately 1.5. There is no indication of the presence of cloud streets typically associated with the rolls, which is a consequence of the dry air advection in the lower troposphere resulting from the downslope flow.

  2. Plasma levels of pollutants are much higher in loggerhead turtle populations from the Adriatic Sea than in those from open waters (Eastern Atlantic Ocean).

    PubMed

    Bucchia, Matteo; Camacho, María; Santos, Marcelo R D; Boada, Luis D; Roncada, Paola; Mateo, Rafael; Ortiz-Santaliestra, Manuel E; Rodríguez-Estival, Jaime; Zumbado, Manuel; Orós, Jorge; Henríquez-Hernández, Luis A; García-Álvarez, Natalia; Luzardo, Octavio P

    2015-08-01

    In this paper we determined the levels of 63 environmental contaminants, including organic (PCBs, organochlorine pesticides, and PAHs) and inorganic (As, Cd, Cu, Pb, Hg and Zn) compounds in the blood of loggerhead turtles (Caretta caretta) from two comparable populations that inhabit distinct geographic areas: the Adriatic Sea (Mediterranean basin) and the Canary Islands (Eastern Atlantic Ocean). All animals were sampled at the end of a period of rehabilitation in centers of wildlife recovery, before being released back into the wild, so they can be considered to be in good health condition. The dual purpose of this paper is to provide reliable data on the current levels of contamination of this species in these geographic areas, and secondly to compare the results of both populations, as it has been reported that marine biota inhabiting the Mediterranean basin is exposed to much higher pollution levels than that which inhabit in other areas of the planet. According to our results it is found that current levels of contamination by organic compounds are considerably higher in Adriatic turtles than in the Atlantic ones (∑PCBs, 28.45 vs. 1.12ng/ml; ∑OCPs, 1.63 vs. 0.19ng/ml; ∑PAHs, 13.39 vs. 4.91ng/ml; p<0.001 in all cases). This is the first time that levels of PAHs are reported in the Adriatic loggerheads. With respect to inorganic contaminants, although the differences were not as great, the Adriatic turtles appear to have higher levels of some of the most toxic elements such as mercury (5.74 vs. 7.59μg/ml, p<0.01). The results of this study confirm that the concentrations are larger in turtles from the Mediterranean, probably related to the high degree of anthropogenic pressure in this basin, and thus they are more likely to suffer adverse effects related to contaminants. PMID:25863507

  3. Occurrences of igneous rocks in the Adriatic Sea: a possible indicator of the Paleozoic supercontinent disintegration

    NASA Astrophysics Data System (ADS)

    Kudrna Prašek, Marko; Petrinec, Zorica; Balen, Dražen

    2014-05-01

    stratification inside the igneous body, together with a varying degree of alteration (chloritization, uralitization, prehnitization, albitization) and weathering, resulted in slight diversification between the studied sites/samples. The samples gathered during this research are compared to those of wider Mediterranean area (particularly with Moroccan localities) related to the rifting system that lead to the continental breakup and the formation of the oceanic domain. Data obtained here indicate an existing connection between those localities i.e. petrogenetic processes. When all geochemical characteristics are put into previously published, although wide, age context (K-Ar and Ar-Ar ages; ranging 276-200 Ma), correlation of recorded petrogenetic processes with the Triassic magmatism i.e. active continental margin setting (continental breakup) becomes quite tentative. From that perspective these scarce localities inside the Adriatic Sea may be regarded as the easternmost occurrences of Central Atlantic Magmatic Province (CAMP)-like rocks and possibly an important source of information about the processes that accompanied the disintegration of the Paleozoic supercontinent Pangea.

  4. Polychlorinated biphenyls (PCBs) in sediments from the western Adriatic Sea: Sources, historical trends and inventories.

    PubMed

    Combi, Tatiane; Miserocchi, Stefano; Langone, Leonardo; Guerra, Roberta

    2016-08-15

    Sources, historical trends and inventories of polychlorinated biphenyls (PCBs) were investigated in sediments collected in five transects along the north-south axis of the western Adriatic Sea. The concentration of total PCBs (∑28 PCBs) ranged from Adriatic Sea. This is further corroborated by the estimated inventories of PCBs, which were ~4-7 times higher in the Po River prodelta (256ngcm(-2)) in comparison to the middle and southern Adriatic, respectively, and about 100 times higher than the in the deep Adriatic Sea. PMID:27110972

  5. Carbonate chemistry dynamics and biological processes along a river-sea gradient (Gulf of Trieste, northern Adriatic Sea)

    NASA Astrophysics Data System (ADS)

    Ingrosso, Gianmarco; Giani, Michele; Cibic, Tamara; Karuza, Ana; Kralj, Martina; Del Negro, Paola

    2016-03-01

    In this paper we investigated, for two years and with a bi-monthly frequency, how physical, chemical, and biological processes affect the marine carbonate system in a coastal area characterized by high alkalinity riverine discharge (Gulf of Trieste, northern Adriatic Sea, Mediterranean Sea). By combining synoptic measurements of the carbonate system with in situ determinations of the primary production (14C incorporation technique) and secondary prokaryotic carbon production (3H-leucine incorporation) along a river-sea gradient, we showed that the conservative mixing between river endmember and off-shore waters was the main driver of the dissolved inorganic carbon (DIC) distribution and seasonal variation. However, during spring and summer seasons also the influence of biological uptake and release of DIC was significant. In the surface water of June 2012, the spreading and persistence of nutrient-rich freshwater stimulated the primary production (3.21 μg C L- 1 h- 1) and net biological DIC decrease (- 100 μmol kg- 1), reducing the dissolved CO2 concentration and increasing the pHT. Below the pycnocline of August 2012, instead, an elevated bacterial carbon production rate (0.92 μg C L- 1 h- 1) was related with net DIC increase (92 μmol kg- 1), low dissolved oxygen concentration, and strong pHT reduction, suggesting the predominance of bacterial heterotrophic respiration over primary production. The flux of carbon dioxide estimated at the air-sea interface exerted a low influence on the seasonal variation of the carbonate system. A complex temporal and spatial dynamic of the air-sea CO2 exchange was also detected, due to the combined effects of seawater temperature, river discharge, and water circulation. On annual scale the system was a sink of atmospheric CO2. However, in summer and during elevated riverine discharges, the area close to the river's mouth acted as a source of carbon dioxide. Also the wind speed was crucial in controlling the air-sea CO2

  6. The Biodiversity of the Mediterranean Sea: Estimates, Patterns, and Threats

    PubMed Central

    Coll, Marta; Piroddi, Chiara; Steenbeek, Jeroen; Kaschner, Kristin; Ben Rais Lasram, Frida; Aguzzi, Jacopo; Ballesteros, Enric; Bianchi, Carlo Nike; Corbera, Jordi; Dailianis, Thanos; Danovaro, Roberto; Estrada, Marta; Froglia, Carlo; Galil, Bella S.; Gasol, Josep M.; Gertwagen, Ruthy; Gil, João; Guilhaumon, François; Kesner-Reyes, Kathleen; Kitsos, Miltiadis-Spyridon; Koukouras, Athanasios; Lampadariou, Nikolaos; Laxamana, Elijah; López-Fé de la Cuadra, Carlos M.; Lotze, Heike K.; Martin, Daniel; Mouillot, David; Oro, Daniel; Raicevich, Saša; Rius-Barile, Josephine; Saiz-Salinas, Jose Ignacio; San Vicente, Carles; Somot, Samuel; Templado, José; Turon, Xavier; Vafidis, Dimitris; Villanueva, Roger; Voultsiadou, Eleni

    2010-01-01

    The Mediterranean Sea is a marine biodiversity hot spot. Here we combined an extensive literature analysis with expert opinions to update publicly available estimates of major taxa in this marine ecosystem and to revise and update several species lists. We also assessed overall spatial and temporal patterns of species diversity and identified major changes and threats. Our results listed approximately 17,000 marine species occurring in the Mediterranean Sea. However, our estimates of marine diversity are still incomplete as yet—undescribed species will be added in the future. Diversity for microbes is substantially underestimated, and the deep-sea areas and portions of the southern and eastern region are still poorly known. In addition, the invasion of alien species is a crucial factor that will continue to change the biodiversity of the Mediterranean, mainly in its eastern basin that can spread rapidly northwards and westwards due to the warming of the Mediterranean Sea. Spatial patterns showed a general decrease in biodiversity from northwestern to southeastern regions following a gradient of production, with some exceptions and caution due to gaps in our knowledge of the biota along the southern and eastern rims. Biodiversity was also generally higher in coastal areas and continental shelves, and decreases with depth. Temporal trends indicated that overexploitation and habitat loss have been the main human drivers of historical changes in biodiversity. At present, habitat loss and degradation, followed by fishing impacts, pollution, climate change, eutrophication, and the establishment of alien species are the most important threats and affect the greatest number of taxonomic groups. All these impacts are expected to grow in importance in the future, especially climate change and habitat degradation. The spatial identification of hot spots highlighted the ecological importance of most of the western Mediterranean shelves (and in particular, the Strait of

  7. The biodiversity of the Mediterranean Sea: estimates, patterns, and threats.

    PubMed

    Coll, Marta; Piroddi, Chiara; Steenbeek, Jeroen; Kaschner, Kristin; Ben Rais Lasram, Frida; Aguzzi, Jacopo; Ballesteros, Enric; Bianchi, Carlo Nike; Corbera, Jordi; Dailianis, Thanos; Danovaro, Roberto; Estrada, Marta; Froglia, Carlo; Galil, Bella S; Gasol, Josep M; Gertwagen, Ruthy; Gil, João; Guilhaumon, François; Kesner-Reyes, Kathleen; Kitsos, Miltiadis-Spyridon; Koukouras, Athanasios; Lampadariou, Nikolaos; Laxamana, Elijah; López-Fé de la Cuadra, Carlos M; Lotze, Heike K; Martin, Daniel; Mouillot, David; Oro, Daniel; Raicevich, Sasa; Rius-Barile, Josephine; Saiz-Salinas, Jose Ignacio; San Vicente, Carles; Somot, Samuel; Templado, José; Turon, Xavier; Vafidis, Dimitris; Villanueva, Roger; Voultsiadou, Eleni

    2010-01-01

    The Mediterranean Sea is a marine biodiversity hot spot. Here we combined an extensive literature analysis with expert opinions to update publicly available estimates of major taxa in this marine ecosystem and to revise and update several species lists. We also assessed overall spatial and temporal patterns of species diversity and identified major changes and threats. Our results listed approximately 17,000 marine species occurring in the Mediterranean Sea. However, our estimates of marine diversity are still incomplete as yet-undescribed species will be added in the future. Diversity for microbes is substantially underestimated, and the deep-sea areas and portions of the southern and eastern region are still poorly known. In addition, the invasion of alien species is a crucial factor that will continue to change the biodiversity of the Mediterranean, mainly in its eastern basin that can spread rapidly northwards and westwards due to the warming of the Mediterranean Sea. Spatial patterns showed a general decrease in biodiversity from northwestern to southeastern regions following a gradient of production, with some exceptions and caution due to gaps in our knowledge of the biota along the southern and eastern rims. Biodiversity was also generally higher in coastal areas and continental shelves, and decreases with depth. Temporal trends indicated that overexploitation and habitat loss have been the main human drivers of historical changes in biodiversity. At present, habitat loss and degradation, followed by fishing impacts, pollution, climate change, eutrophication, and the establishment of alien species are the most important threats and affect the greatest number of taxonomic groups. All these impacts are expected to grow in importance in the future, especially climate change and habitat degradation. The spatial identification of hot spots highlighted the ecological importance of most of the western Mediterranean shelves (and in particular, the Strait of

  8. Dsp in Moroccan Mediterranean Sea.

    NASA Astrophysics Data System (ADS)

    Rachid, Fadel

    At sea temperate, there is usually a sole major floraison of the phytoplancton (in the spring) that exhausts the available stock of nutritious salt. This phenomenon is natural. It's more known under the name of "red tide or colored waters", it brings about a danger, with hazardous consequences on the wildlife water wildlife. The toxins emitted by certain seaweeds, of this phytoplancton, are transmitted through the trophic chain to man. Sometimes the contamination of these sea fruits provokes empoisoning to the consumers. Sometimes phytoplanctonics efflorescences do not present any significant coloring but can generate an increased liberation of toxins in sea water. The relative concentration of the one here then is detected in the shellfishes. These organisms concentrate the phocotoxines in their hepatopancreas. These are therefore bio potential indicators of the sea environment. We studied, in parallel, the variation of the characteristic abiotics of the Mediterranean sites previously choosen (physico-chimicals parameters and oceanographics parameters) and the variation of the relative toxicity of the bio indicators in every site. It in springs that the zones navies, subjected to important water provisions coming from a river, undergo several excessive floraisons during the spring and the summer, thanks to their continuous supplying in nutriments. We noted that the arrival new water masses. We draw from this that the coastal areas, due to the precipitations of the winter, translates itself at the level of the embouchure of the estuary Oued Laou by the maximum concentration of contained toxins in the shellfishes and that these waters were loaded with drifts of the olive waste, liquid loss abandoned to himself after extraction of the oil of the renowned olives of this region.

  9. Night Views Over the Mediterranean Sea

    NASA Video Gallery

    This video over the Mediterranean Sea was taken by the crew of Expedition 29 aboard the International Space Station. This sequence of shots was taken on Oct. 6, 2011, from 22:58:09 to 23:13:15 GMT,...

  10. Microbial contribution to carbon biogeochemistry in the Central Mediterranean Sea: Variability of activities and biomass

    NASA Astrophysics Data System (ADS)

    La Ferla, Rosabruna; Azzaro, Filippo; Azzaro, Maurizio; Caruso, Gabriella; Decembrini, Franco; Leonardi, Marcella; Maimone, Giovanna; Monticelli, Luis S.; Raffa, Francesco; Santinelli, Chiara; Zaccone, Renata; Ribera d'Alcalà, Maurizio

    2005-08-01

    This paper concerns the current debate as to whether oceans are heterotrophic or autotrophic environments. Microbes are responsible for the assimilation and remineralization of CO 2 in the sea and microbial processes are involved in the Earth climatic change. The variability of microbial biomass and activities were studied in the Mediterranean Sea which represents a suitable basin for mapping the trophic regimes by the study of biogeochemical processes. The surveys were carried out in the epi-, meso- and bathy-pelagic zones of the Central Mediterranean Sea from 1996 to 2002. Bacterial abundance, leucine aminopeptidase (LAP) and β-glucosidase (β-GLU) activities, bacterial carbon production (BCP), community respiration (R) and primary production (PP) were the main parameters investigated. Biomass and activities seasonally varied in epipelagic and, to some extent, in meso- and bathy-pelagic layers too and several trophic ratios were determined, showing different scenarios in the different areas and seasons. In the euphotic layer, bacterial growth efficiency (BGE) widely ranged between 4% and 50% showing a decreasing trend from estuaries towards pelagic areas in alignment with the trophic gradient from the Northern Adriatic to the Ionian Sea. However, BGE did not correlate to PP and temperature. The Central Mediterranean Sea showed different trophic regimes in the examined areas and seasons. In the Northern Adriatic Sea in winter, the trophic balance appeared to move towards autotrophy and a positive C budget resulted. An opposite scenario happened in summer when the trophic balance moved to heterotrophy and a negative C budget occurred. In the Ionian Sea, the overall balance turned always towards remineralization. However, on annual time scale, the Central Mediterranean Sea seems to show a tendency towards a heterotrophic system.

  11. The carbon budget in the northern Adriatic Sea, a winter case study

    NASA Astrophysics Data System (ADS)

    Catalano, G.; Azzaro, M.; Bastianini, M.; Bellucci, L. G.; Bernardi Aubry, F.; Bianchi, F.; Burca, M.; Cantoni, C.; Caruso, G.; Casotti, R.; Cozzi, S.; Del Negro, P.; Fonda Umani, S.; Giani, M.; Giuliani, S.; Kovacevic, V.; La Ferla, R.; Langone, L.; Luchetta, A.; Monticelli, L. S.; Piacentino, S.; Pugnetti, A.; Ravaioli, M.; Socal, G.; Spagnoli, F.; Ursella, L.

    2014-07-01

    This paper presents a winter carbon budget for the northern Adriatic Sea, obtained through direct measurements during two multidisciplinary cruises and literature data. A box model approach was adopted to integrate estimates of stocks and fluxes of carbon species over the total area. The oligotrophy at the basin scale and the start of primary productivity well before the onset of spring stratification were observed. In winter, the system underwent a complete reset, as the mixing of water masses erased any signal of previous hypoxia or anoxia episodes. The northern Adriatic Sea was phosphorus depleted with respect to C and N availability. This fact confirms the importance of mixing with deep-sea water for P supply to biological processes on the whole. Despite the abundant prokaryotic biomass, the microbial food web was less efficient in organic C production than phytoplankton. In the upper layer, the carbon produced by primary production exceeded the fraction respired by planktonic community smaller than 200 µm. On the contrary, respiration processes prevailed in the water column below the pycnocline. The carbon budget also proved that the northern Adriatic Sea can be an effective sink for atmospheric CO2 throughout the entire winter season.

  12. Cadmium and lead in selected tissues of two commercially important fish species from the Adriatic Sea.

    PubMed

    Gaspić, Z Kljaković; Zvonarić, T; Vrgoc, N; Odzak, N; Barić, A

    2002-12-01

    Baseline levels of cadmium and lead were determined in muscle tissue and liver of hake (Merluccius merluccius) and red mullet (Mullus barbatus), two commercially important fish species from the eastern Adriatic. Concentrations of trace metals in liver (Cd: 6-183 microg kg(-1) w. wt. ; Pb: 39-970 microg kg(-1) w. wt.) were within the range of recently published data for the Mediterranean. In the muscle tissue, cadmium concentrations (4.1-29 microg kg(-1) w. wt.) were among the lowest reported values for the Mediterranean, whereas lead levels (49-158 microg kg(-1) w. wt.) were within the range of values reported for various coastal areas of the Mediterranean. Presented data on cadmium and lead content in the studied fish species provide no proof of the general pollution of the Adriatic. Obtained data were tested in relation to fish length. Metal concentrations in liver decreased with the increase in fish size, whereas no significant correlation was found between trace metal levels in the muscle tissue and the length of both species. Relationships between metal concentrations and sex were also tested, but they gave no significant results. A comparison of contaminant concentrations in the edible tissue of hake and red mullet with the Croatian legislation shows that the consumption of their meat is not harmful for humans, not even for the most endangered population from the coastal region. PMID:12448550

  13. Polybrominated diphenyl ethers in mussels (Mytilus galloprovincialis) collected from Central Adriatic Sea.

    PubMed

    Piersanti, Arianna; Tavoloni, Tamara; Bastari, Eleonora; Lestingi, Carmela; Romanelli, Sara; Saluti, Giorgio; Moretti, Simone; Galarini, Roberta

    2015-12-15

    One-hundred and thirty-four samples of mussels (Mytilus galloprovincialis) collected along Central Adriatic Sea in 2013 were examined to determine the levels of fifteen congeners of polybrominated diphenyl ethers (PBDEs). The purified samples were analysed by gas-chromatography coupled to tandem mass spectrometry (GC-MS/MS) applying the isotopic dilution. Only four congeners (PBDE 47, PBDE 99, PBDE 49 and PBDE 100) were present above the established limits of quantification with mean concentrations equal to 73, 30, 19 and 18 pg g(-1), respectively. The concentrations of PBDEs (sum) ranged from 27 to 386 pg g(-1), with the highest levels around the coastal area of Ancona town. The here found levels were comparable to those measured in mussels collected along Southern Adriatic Sea. PMID:26497256

  14. Underwater noise assessment in the Gulf of Trieste (Northern Adriatic Sea, Italy) using an MSFD approach.

    PubMed

    Codarin, Antonio; Picciulin, Marta

    2015-12-30

    In the marine environment, underwater noise is one of the most widespread input of man-made energy. Recently, the European Commission has stressed the necessity of establishing threshold levels as a target for the descriptor 11.2.1 "Continuous low frequency sounds" in the Marine Strategy Framework Directive (MSFD). In 2012, a monthly underwater noise monitoring programme was conducted in the Gulf of Trieste (Northern Adriatic Sea, Italy); the collected acoustic samples (frequency range: 10-20,000 Hz) were analysed in the 1/3 octave bands. The stations have been further clustered following the 63 and 125 Hz bands noise levels. Average SPL levels resulted similar to those previously computed for proximate areas, indicating that the Adriatic Sea sub-region experiences high noise pressure in the marine waters. In its turn this claims for a scientific and technical international cooperation, as requested by the EU programme. No seasonal variation in local noise levels has been found. PMID:26506026

  15. Near-field dispersion of produced formation water (PFW) in the Adriatic Sea: an integrated numerical-chemical approach.

    PubMed

    Cianelli, D; Manfra, L; Zambianchi, E; Maggi, C; Cappiello, A; Famiglini, G; Mannozzi, M; Cicero, A M

    2008-05-01

    Produced formation waters (PFWs), a by-product of both oil and gas extraction, are separated from hydrocarbons onboard oil platforms and then discharged into the sea through submarine outfalls. The dispersion of PFWs into the environment may have a potential impact on marine ecosystems. We reproduce the initial PFW-seawater mixing process by means of the UM3 model applied to offshore natural gas platforms currently active in the Northern Adriatic Sea (Mediterranean Sea). Chemical analyses lead to the identification of a chemical tracer (diethylene glycol) which enables us to follow the fate of PFWs into receiving waters. The numerical simulations are realized in different seasonal conditions using both measured oceanographic data and tracer concentrations. The numerical results show the spatial and temporal plume development in different stratification and ambient current conditions. The analytical approach measures concentrations of the diethylene glycol at a maximum sampling distance of 25 m. The results show a good agreement between field observations and model predictions in the near-field area. The integration of numerical results with chemical analyses also provides new insight to plan and optimize PFW monitoring and discharge. PMID:18289661

  16. Geochemistry of sediments in the Northern and Central Adriatic Sea

    NASA Astrophysics Data System (ADS)

    De Lazzari, A.; Rampazzo, G.; Pavoni, B.

    2004-03-01

    Major, minor and trace elements, loss of ignition, specific surface area, quantities of calcite and dolomite, qualitative mineralogical composition, grain-size distribution and organic micropollutants (PAH, PCB, DDT) were determined on surficial marine sediments sampled during the 1990 ASCOP (Adriatic Scientific Cooperative Program) cruise. Mineralogical composition and carbonate content of the samples were found to be comparable with data previously reported in the literature, whereas geochemical composition and distribution of major, minor and trace elements for samples in international waters and in the central basin have never been reported before. The large amount of information contained in the variables of different origin has been processed by means of a comprehensive approach which establishes the relations among the components through the mathematical-statistical calculation of principal components (factors). These account for the major part of data variance loosing only marginal parts of information and are independent from the units of measure. The sample descriptors concerning natural components and contamination load are discussed by means of a statistical model based on an R-mode Factor analysis calculating four significant factors which explain 86.8% of the total variance, and represent important relationships between grain size, mineralogy, geochemistry and organic micropollutants. A description and an interpretation of factor composition is discussed on the basis of pollution inputs, basin geology and hydrodynamics. The areal distribution of the factors showed that it is the fine grain-size fraction, with oxides and hydroxides of colloidal origin, which are the main means of transport and thus the principal link between chemical, physical and granulometric elements in the Adriatic.

  17. Storm surges in the Mediterranean Sea: Variability and trends under future climatic conditions

    NASA Astrophysics Data System (ADS)

    Androulidakis, Yannis S.; Kombiadou, Katerina D.; Makris, Christos V.; Baltikas, Vassilis N.; Krestenitis, Yannis N.

    2015-09-01

    The trends of storm surge extremes in the Mediterranean Sea for a period of 150 years (1951-2100) are explored, using a high-resolution storm surge model. Numerical simulations are forced by the output of regional climate simulations with RegCM3, which uses IPCC's historical data on greenhouse gasses emissions for the (past) period 1951-2000, and IPCC's A1B climate scenario for the (future) period 2001-2100. Comparisons between observations and modeling results show good agreement and confirm the ability of our model to estimate the response of the sea surface to future climatic conditions. We investigate the future trends, the variability and frequency of local extremes and the main forcing mechanisms that can induce strong surges in the Mediterranean region. Our results support that there is a general decreasing trend in storminess under the considered climate scenario, mostly related to the frequency of local peaks and the duration and spatial coverage of the storm surges. The northward shift in the location of storm tracks is a possible reason for this storminess attenuation, especially over areas where the main driving factor of extreme events is the inverted barometer effect. However, the magnitudes of sea surface elevation extremes may increase in several Mediterranean sub-regions, i.e., Southern Adriatic, Balearic and Tyrrhenian Seas, during the 21st century. There are clear distinctions in the contributions of winds and pressure fields to the sea level height for various regions of the Mediterranean Sea, as well as on the seasonal variability of extreme values; the Aegean and Adriatic Seas are characteristic examples, where high surges are predicted to be mainly induced by low pressure systems and favorable winds, respectively.

  18. Electronic Tagging of Atlantic Bluefin Tuna (Thunnus thynnus, L.) Reveals Habitat Use and Behaviors in the Mediterranean Sea

    PubMed Central

    Cermeño, Pablo; Quílez-Badia, Gemma; Ospina-Alvarez, Andrés; Sainz-Trápaga, Susana; Boustany, Andre M.; Seitz, Andy C.; Tudela, Sergi; Block, Barbara A.

    2015-01-01

    We analyzed the movements of Atlantic tuna (Thunnus thynnus L.) in the Mediterranean Sea using data from 2 archival tags and 37 pop-up satellite archival tags (PAT). Bluefin tuna ranging in size from 12 to 248 kg were tagged on board recreational boats in the western Mediterranean and the Adriatic Sea between May and September during two different periods (2000 to 2001 and 2008 to 2012). Although tuna migrations between the Mediterranean Sea and the Atlantic Ocean have been well reported, our results indicate that part of the bluefin tuna population remains in the Mediterranean basin for much of the year, revealing a more complex population structure. In this study we demonstrate links between the western Mediterranean, the Adriatic and the Gulf of Sidra (Libya) using over 4336 recorded days of location and behavior data from tagged bluefin tuna with a maximum track length of 394 days. We described the oceanographic preferences and horizontal behaviors during the spawning season for 4 adult bluefin tuna. We also analyzed the time series data that reveals the vertical behavior of one pop-up satellite tag recovered, which was attached to a 43.9 kg tuna. This fish displayed a unique diving pattern within 16 days of the spawning season, suggesting a use of the thermocline as a thermoregulatory mechanism compatible with spawning. The results obtained hereby confirm that the Mediterranean is clearly an important habitat for this species, not only as spawning ground, but also as an overwintering foraging ground. PMID:25671316

  19. Electronic tagging of Atlantic bluefin tuna (Thunnus thynnus, L.) reveals habitat use and behaviors in the Mediterranean Sea.

    PubMed

    Cermeño, Pablo; Quílez-Badia, Gemma; Ospina-Alvarez, Andrés; Sainz-Trápaga, Susana; Boustany, Andre M; Seitz, Andy C; Tudela, Sergi; Block, Barbara A

    2015-01-01

    We analyzed the movements of Atlantic tuna (Thunnus thynnus L.) in the Mediterranean Sea using data from 2 archival tags and 37 pop-up satellite archival tags (PAT). Bluefin tuna ranging in size from 12 to 248 kg were tagged on board recreational boats in the western Mediterranean and the Adriatic Sea between May and September during two different periods (2000 to 2001 and 2008 to 2012). Although tuna migrations between the Mediterranean Sea and the Atlantic Ocean have been well reported, our results indicate that part of the bluefin tuna population remains in the Mediterranean basin for much of the year, revealing a more complex population structure. In this study we demonstrate links between the western Mediterranean, the Adriatic and the Gulf of Sidra (Libya) using over 4336 recorded days of location and behavior data from tagged bluefin tuna with a maximum track length of 394 days. We described the oceanographic preferences and horizontal behaviors during the spawning season for 4 adult bluefin tuna. We also analyzed the time series data that reveals the vertical behavior of one pop-up satellite tag recovered, which was attached to a 43.9 kg tuna. This fish displayed a unique diving pattern within 16 days of the spawning season, suggesting a use of the thermocline as a thermoregulatory mechanism compatible with spawning. The results obtained hereby confirm that the Mediterranean is clearly an important habitat for this species, not only as spawning ground, but also as an overwintering foraging ground. PMID:25671316

  20. Multidecadal variability of atmospheric pressure and wind contribution to storm surges in the northern Adriatic Sea.

    NASA Astrophysics Data System (ADS)

    Raicich, Fabio

    2010-05-01

    The northern Adriatic Sea is very sensitive to sea level changes since most of the coastal areas is low and subject to floods. In addition to natural subsidence, the northwestern Adriatic coast, including the Venice Lagoon and the area around Marina di Ravenna, has been affected by anthropogenic subsidence due to the extraction of underground water and gas, particularly during the 1930-1970 period. In this work we will study the time variability of Adriatic sea level using daily means, trying to identify the different contributions of atmospheric pressure and wind to storm surges in the northern basin. A storm surge event corresponds to a positive peak in the time series of daily mean sea level; secondary peaks within ±2 days from the main peak are discarded since they are attributed to the same storm. Daily sea level variability is studied using Empirical Orthogonal Functions and is connected with atmospheric pressure from NCEP reanalyses and wind stress from NCEP reanalyses and scatterometer data. Different sea level data sets are analysed, varying the number of sea level stations and/or the time series span, since the data coverage is uneven in space and time. The EOF analysis of the various data sets provides coherent results with regard to the two main modes, that together explain between 70 and 85% of total variance. The first mode explains 55-69% of total variance and consists of uniform sea level variability all over the basin, correlated with atmospheric pressure through the inverted barometer effect. The second mode explains 14-16% of variance and accounts for an along-basin sea level gradient, which is correlated with the meridional wind stress component. The first two Principal Components are used as proxies to pressure- and wind-induced components of storm surges in the northern Adriatic. The frequency of the most remarkable events is analysed, choosing the 1%, 5% and 10% highest daily mean sea level to represent events of decreasing strength (on

  1. Variability of mesoscale features in the Mediterranean Sea from XBT data analysis

    NASA Astrophysics Data System (ADS)

    Fusco, G.; Manzella, G. M. R.; Cruzado, A.; Gacic, M.; Gasparini, G. P.; Kovacevic, V.; Millot, C.; Tziavos, C.; Velasquez, Z. R.; Walne, A.; Zervakis, V.; Zodiatis, G.

    2003-01-01

    During the period 1998-2000, the Mediterranean Forecasting System Pilot Project, aiming to build a forecasting system for the physical state of the sea, has been carried out. A ship-of-opportunity programme sampled the Mediterranean upper ocean thermal structure by means of eXpendable Bathy-Thermographs (XBTs), along seven tracks, from September 1999 to May 2000. The tracks were designed to detect some of the main circulation features, such as the stream of surface Atlantic water flowing from the Alboran Sea to the Eastern Levantine Basin. The cyclonic gyres in the Liguro-Provenal Basin, the southern Adriatic and Ionian Seas and the anticyclonic gyres in the Levantine Basin were also features to be detected.

  2. Intense air-sea exchange and heavy rainfall: impact of the northern Adriatic SST

    NASA Astrophysics Data System (ADS)

    Stocchi, P.; Davolio, S.

    2016-02-01

    Over the northern Adriatic basin, intense air-sea interactions are often associated with heavy precipitation over the mountainous areas surrounding the basin. In this study, a high-resolution mesoscale model is employed to simulate three severe weather events and to evaluate the effect of the sea surface temperature on the intensity and location of heavy rainfall. The sensitivity tests show that the impact of SST varies among the events and it mainly involves the modification of the PBL characteristics and thus the flow dynamics and its interaction with the orography.

  3. Low frequency Sea Level Variability: correlation between altimetry and tide gauges in the Mediterranean Sea

    NASA Astrophysics Data System (ADS)

    Bonaduce, A.; Pinardi, N.

    2012-04-01

    Sea level variability in the Mediterranean Sea over the decadal time scale is studied using a combination of sea level and in-situ observations. A method to decompose the different sea level signals for tide gauges and altimetry is proposed, so that a coherent comparison between the two measurements is possible. The steric component and the atmospheric pressure contribution (inverse barometer) are filtered in order to look at sea level changes over decadal time scales. Low frequency sea level from tide gauges data is found to be representative of a large scale signal and results to be comparable, along all the basin, with satellite altimetry data. In particular the two signals are better correlated in the areas where the continental shelf is extended, such as the northern Adriatic. The same occurs in the case where the tide gauge station is located on an island, such as Malta, where the station is representative of the open ocean sea level signal. Moving towards the Levantin basin, the shelves extension generally decrease and the two data sets tend to be less correlated even if still correlated positively with a root mean square error lower than 5 cm (Hadera, Israel). Looking at the sea level trend, a positive trend of 2.15 ± 0.7 mm yr -1 is observed in the Mediterranean basin considering satellite altimetry during the period from 1993 to 2010 . Glacial Isostatic Adjustment (GIA) has been considered correcting sea level data with ICE-5G model data. This value represent just and index of the sea level changes occurring at basin scale. The basin presents a marked trend spatial variability, mainly characterized by strong positive trends in the shelves areas and negative trends in the Ionian sea, due to a strong change in the circulation in this basin. The variability of the trend values as a function of the number of years considered is such that at least 15 years of data are needed in order to obtain a significant and stable positive trend. The total lack of in

  4. Observed and modeled surface Lagrangian transport between coastal regions in the Adriatic Sea with implications for marine protected areas

    NASA Astrophysics Data System (ADS)

    Carlson, Daniel F.; Griffa, Annalisa; Zambianchi, Enrico; Suaria, Giuseppe; Corgnati, Lorenzo; Magaldi, Marcello G.; Poulain, Pierre-Marie; Russo, Aniello; Bellomo, Lucio; Mantovani, Carlo; Celentano, Paolo; Molcard, Anne; Borghini, Mireno

    2016-04-01

    Surface drifters and virtual particles are used to investigate transport between seven coastal regions in the central and southern Adriatic Sea to estimate the degree to which these regions function as a network. Alongshore coastal currents and cyclonic gyres are the primary circulation features that connected regions in the Adriatic Sea. The historical drifter observations span 25 years and, thus, provide estimates of transport between regions realized by the mean surface circulation. The virtual particle trajectories and a dedicated drifter experiment show that southeasterly Sirocco winds can drive eastward cross-Adriatic transport from the Italian coast near the Gargano Promontory to the Dalmatian Islands in Croatia. Southeasterly winds disrupt alongshore transport on the west coast. Northwesterly Mistral winds enhanced east-to-west transport and resulted in stronger southeastward coastal currents in the western Adriatic current (WAC) and export to the northern Ionian Sea. The central Italian regions showed strong connections from north to south, likely realized by alongshore transport in the WAC. Alongshore, downstream transport was weaker on the east coast, likely due to the more complex topography introduced by the Dalmatian Islands of Croatia. Cross-Adriatic connection percentages were higher for east-to-west transport. Cross-Adriatic transport, in general, occurred via the cyclonic sub-gyres, with westward (eastward) transport observed in the northern (southern) arms of the central and southern gyres.

  5. Sea level rise of semi-enclosed basins: deviation of Adriatic and Baltic sea level from the mean global value.

    NASA Astrophysics Data System (ADS)

    Scarascia, Luca; Lionello, Piero

    2015-04-01

    Future sea level rise (SL), which represents today one of the major threats that are caused by climate change, will not be uniform. Regional differences are crucial for 40% of the world population, which is located in the coastal zone. To explore the mechanisms linking regional SL to climate variables is very important in order to provide reliable future projections. This study focuses on two semi-enclosed basins, the Adriatic and Baltic Sea and investigates the deviation of their SL from the mean global value. In fact, past deviations of the SL of these two basins from the global value have been observed and can be attributed to large scale factors (such as teleconnections) and regional factors, such as the inverse barometric effect, the wind stress, the thermosteric and halosteric effects. The final goal of this work is to assess to which extent the Adriatic and Baltic SL will depart from the mean global value in the next decades and at the end of 21st century. This is achieved by analyzing deviations of the mean SL of the Baltic and Adriatic Sea from the global mean SL during the 20th century and investigating which factors can explain such deviations. A multivariate linear regression model is built and used to describe the link between three large scale climate variables which are used as predictors (mean sea level pressure, surface air temperature and precipitation), and the regional SL deviation (the predictand), computed as the difference between the regional and the global SL. At monthly scale this linear regression model provides a good reconstruction of the past variability in the cold season during which it explains 60%-70% of the variance. Summer reconstruction is substantially less successful and it represents presently the main limit of the model skill. This linear regression model, forced by predictors extracted from CMIP5 multi-model simulations, is used to provide projections of SL in the Adriatic and Baltic Sea. On the basis of the projections

  6. Eutrophication in the northern Adriatic Sea: Benthic fluxes and nutrient budgets

    SciTech Connect

    Berelson, W.M.; Hammond, D.E. ); Giordani, P. )

    1990-01-09

    The northern Adriatic Sea has been plagued by problems of eutrophication. This area is relatively shallow (maximum depth = 60m), becoming stratified during the summer months which inhibits oxygen transport to bottom waters. Anthropogenic nutrient loading in rivers entering the northern Adriatic has increased nutrient input to this system and stimulated algai growth. Five stations in the western Adriatic (south of the Po River Delta) were occupied during September, 1988 and benthic flux chambers used to measure nutrient fluxes. These sites included 3 stations previously studied in 1982. Flux measurements of dissolved silica, nitrate, oxygen, ammonia, phosphate, CO[sub 2], alkalinity and radon were made during 24 hour incubations of flux chambers (area covered - 0.07 m[sup 2], volume = [approximately]81) that were continuously stirred and sampled periodically. Nutrient fluxes measured were generally consistent with the fluxes measured previously in June, 1982 except for radon fluxes which were 203 times greater in the earlier field season. There was a general trend in nutrient fluxes to decrease offshore, a pattern probably controlled by the sedimentation patterns because fine grained, organic matter-rich sediment are concentrated in a zone near shore. Average regional fluxes were (in mmol m[sup -2]d[sup -1], negative values indicate flux into sediment): Oxygen (-12), CO[sub 2] (19), Alkalinity (4), Silica (3.3), Ammonia (1.5), Phosphate (0.1) and Nitrate (0.3). The carbon/ammonia flux ratio is about twice the C/N ratio in marine phytoplankton, suggesting that large amounts of denitrification may be occuring in these sediments. Comparisons of benthic fluxes and sediment burial rates indicate that 50-90% of the carbon, silica, phosphorus and nitrogen arriving at the sediment-water interface is recycled before burial. The nutrient input to the water column from NW Adriatic sediments is about equal to the input from coastal rivers.

  7. Towards integrated assessment of the northern Adriatic Sea sediment budget using remote sensing

    NASA Astrophysics Data System (ADS)

    Taramelli, A.; Filipponi, F.; Valentini, E.; Zucca, F.; Gutierrez, O. Q.; Liberti, L.; Cordella, M.

    2014-12-01

    Understanding the factors influencing sediment fluxes is a key issue to interpret the evolution of coastal sedimentation under natural and human impact and relevant for the natural resources management. Despite river plumes represent one of the major gain in sedimentary budget of littoral cells, knowledge of factors influencing complex behavior of coastal plumes, like river discharge characteristics, wind stress and hydro-climatic variables, has not been yet fully investigated. Use of Earth Observation data allows the identification of spatial and temporal variations of suspended sediments related to river runoff, seafloor erosion, sediment transport and deposition processes. Objective of the study is to investigate sediment fluxes in northern Adriatic Sea by linking suspended sediment patterns of coastal plumes to hydrologic and climatic forcing regulating the sedimentary cell budget and geomorphological evolution in coastal systems and continental shelf waters. Analysis of Total Suspended Matter (TSM) product, derived from 2002-2012 MERIS time series, was done to map changes in spatial and temporal dimension of suspended sediments, focusing on turbid plume waters and intense wind stress conditions. From the generated multi temporal TSM maps, dispersal patterns of major freshwater runoff plumes in northern Adriatic Sea were evaluated through spatial variability of coastal plumes shape and extent. Additionally, sediment supply from river distributary mouths was estimated from TSM and correlated with river discharge rates, wind field and wave field through time. Spatial based methodology has been developed to identify events of wave-generated resuspension of sediments, which cause variation in water column turbidity, occurring during intense wind stress and extreme metocean conditions, especially in the winter period. The identified resuspension events were qualitatively described and compared with to hydro-climatic variables. The identification of spatial and

  8. Molluscan shell communities: a window into the ecological history of the northern Adriatic Sea

    NASA Astrophysics Data System (ADS)

    Gallmetzer, Ivo; Haselmair, Alexandra; Tomasovych, Adam; Stachowitsch, Michael; Zuschin, Martin

    2015-04-01

    The historical ecology approach used in the present study sheds light on the younger ecological history of the northern Adriatic Sea, targeting the period of the last 500 to 1500 years. We focus on down-core changes in molluscan death assemblages, where differences between community structures serve as a proxy for ecological shifts over time. The northern Adriatic Sea, with its densely populated shoreline, is among the most degraded marine ecosystems worldwide and is therefore particularly suited to study ecosystem modification under human pressure. Multiple cores of 1.5 m length and diameters of 90 and 160 mm were taken at seven sampling stations throughout the northern Adriatic Sea, covering different sediment types, nutrient conditions and degrees of exploitation. For the mollusc analyses, the cores were sliced into smaller subsamples and analysed for species composition, abundance, taxonomic similarity, evidence for ecological interactions (i.e., frequencies of drilling predation) and taphonomic condition of shells. Sediment analyses include granulometry and radiometric sediment dating using Pb 210. Sediment age analysis revealed one-order-of-magnitude differences in sedimentation rates between stations (34 mm/yr at the Po delta, Italy, 1.5 mm/yr at Brijuni islands, Croatia). In total, 114 bivalve and 112 gastropod species were recorded. Bivalve assemblages showed significant interregional differences that are strongly correlated with sedimentation rates and sediment composition. Down-core changes in molluscan communities are conspicuous in all cores, particularly in the uppermost core sections. This information, together with radiometric shell dating for selected species, helps to specify the timing of major ecological changes in the past and define pristine benthic communities as references for future conservation and management efforts.

  9. Genetic connectivity between land and sea: the case of the beachflea Orchestia montagui (Crustacea, Amphipoda, Talitridae) in the Mediterranean Sea

    PubMed Central

    2013-01-01

    Introduction We examined patterns of genetic divergence in 26 Mediterranean populations of the semi-terrestrial beachflea Orchestia montagui using mitochondrial (cytochrome oxidase subunit I), microsatellite (eight loci) and allozymic data. The species typically forms large populations within heaps of dead seagrass leaves stranded on beaches at the waterfront. We adopted a hierarchical geographic sampling to unravel population structure in a species living at the sea-land transition and, hence, likely subjected to dramatically contrasting forces. Results Mitochondrial DNA showed historical phylogeographic breaks among Adriatic, Ionian and the remaining basins (Tyrrhenian, Western and Eastern Mediterranean Sea) likely caused by the geological and climatic changes of the Pleistocene. Microsatellites (and to a lesser extent allozymes) detected a further subdivision between and within the Western Mediterranean and the Tyrrhenian Sea due to present-day processes. A pattern of isolation by distance was not detected in any of the analyzed data set. Conclusions We conclude that the population structure of O. montagui is the result of the interplay of two contrasting forces that act on the species population genetic structure. On one hand, the species semi-terrestrial life style would tend to determine the onset of local differences. On the other hand, these differences are partially counter-balanced by passive movements of migrants via rafting on heaps of dead seagrass leaves across sites by sea surface currents. Approximate Bayesian Computations support dispersal at sea as prevalent over terrestrial regionalism. PMID:23618554

  10. Probing continental collision in the Mediterranean Sea

    NASA Astrophysics Data System (ADS)

    Robertson, A. H. F.

    Knowledge about the processes of continental collisional would unlock a wealth of data for the field of tectonics, but such processes have been poorly documented by academic ocean drilling. On the basis of 1993 data confirming that the easternmost Mediterranean is in the initial stages of continental collision, the Ocean Drilling Program has scheduled two legs of drilling for summer 1995 in the eastern and western parts of the Mediterranean Sea.Effects of continental collision in the easternmost Mediterranean include the Quaternary uplift of Cyprus [Poole and Robertson, 1991] and the break up and subsidence of the Eratosthenes Seamount, which is located in the easternmost Mediterranean between Cyprus and the Levantine Basin (Figure 1).

  11. Paleozoic to modern marine ecological shift displayed in the northern Adriatic Sea

    NASA Astrophysics Data System (ADS)

    McKinney, Frank K.; Hageman, Steven J.

    2006-10-01

    One of the major changes in the history of life was the decline from abundant sedentary, suspension-feeding animals living on the seafloor during the Paleozoic to their relative scarcity afterward, while animal life within the sediment burgeoned after the end-Paleozoic extinction. In the northern Adriatic Sea there is a quantitative change from abundant exposed sedentary suspension feeders in eastern oligotrophic water to their virtual absence under western higher-nutrient waters, where prolific animal life occurs within sediments. This geographic gradient supports the hypothesis that an increase in neritic nutrients drove—and continues to drive—the Paleozoic to post-Paleozoic marine ecological transition.

  12. Genetic identification of a rare record of Ommastrephes Bartramii (Cephalopoda: Ommastrephidae) from the Eastern Adriatic Sea.

    PubMed

    Franjević, Damjan; Skaramuca, Daria; Katavić, Vedran; Rajević, Nives; Skaramuca, Boško

    2015-01-01

    The neon flying squid Ommastrephes bartramii Lesueur, 1821 belongs to the Ommastrephidae, Cephalopoda family. The family Ommastrephidae (Mollusca: Cephalopoda) includes many commercially important species, dispersed around the world. The Ommastrephidae family is conventionally divided into three subfamilies (Illicinae, Todarodinae, and Ommastrephinae). We report a specimen of neon flying squid caught in the winter 2013 at Luka Šipanska, Island of Šipan, Croatia and identified at the genetic level using the standard mitochondrial COI barcode region. This record represents the first genetic identification of a neon flying squid from the Adriatic Sea. PMID:26103681

  13. Verification of an ensemble prediction system for storm surge forecast in the Adriatic Sea

    NASA Astrophysics Data System (ADS)

    Mel, Riccardo; Lionello, Piero

    2014-12-01

    In the Adriatic Sea, storm surges present a significant threat to Venice and to the flat coastal areas of the northern coast of the basin. Sea level forecast is of paramount importance for the management of daily activities and for operating the movable barriers that are presently being built for the protection of the city. In this paper, an EPS (ensemble prediction system) for operational forecasting of storm surge in the northern Adriatic Sea is presented and applied to a 3-month-long period (October-December 2010). The sea level EPS is based on the HYPSE (hydrostatic Padua Sea elevation) model, which is a standard single-layer nonlinear shallow water model, whose forcings (mean sea level pressure and surface wind fields) are provided by the ensemble members of the ECMWF (European Center for Medium-Range Weather Forecasts) EPS. Results are verified against observations at five tide gauges located along the Croatian and Italian coasts of the Adriatic Sea. Forecast uncertainty increases with the predicted value of the storm surge and with the forecast lead time. The EMF (ensemble mean forecast) provided by the EPS has a rms (root mean square) error lower than the DF (deterministic forecast), especially for short (up to 3 days) lead times. Uncertainty for short lead times of the forecast and for small storm surges is mainly caused by uncertainty of the initial condition of the hydrodynamical model. Uncertainty for large lead times and large storm surges is mainly caused by uncertainty in the meteorological forcings. The EPS spread increases with the rms error of the forecast. For large lead times the EPS spread and the forecast error substantially coincide. However, the EPS spread in this study, which does not account for uncertainty in the initial condition, underestimates the error during the early part of the forecast and for small storm surge values. On the contrary, it overestimates the rms error for large surge values. The PF (probability forecast) of the EPS

  14. Trichoptera biodiversity of the Aegean and Adriatic sea basins in the republic of Kosovo.

    PubMed

    Ibrahimi, Halil; Kučinić, Mladen; Gashi, Agim; Grapci-Kotori, Linda

    2014-01-01

    We present the first preliminary inventory of Trichoptera taxa in the Aegean and Adriatic Sea basins in Kosovo that have previously received poor and fragmentary attention. Adult caddisflies were collected using ultraviolet (UV) light traps in 13 stations in areas of the Aegean Sea and Adriatic Sea drainage basins in Kosovo. Nineteen species out of 82, reported in this article, are first records for the Kosovo caddisfly fauna. Five genera are recorded for the first time in Kosovo: Brachycentrus, Ecclisopteryx, Psilopteryx, Thremma, and Oecetis. During this investigation, we found several Southeastern European endemic and rare species whose previous known distribution was limited to particular areas of this region, as well as other species whose distribution is considerably enlarged by this investigation: Polycentropus ierapetra, Polycentropus irroratus, Chaetopteryx stankovici, Drusus schmidi, Drusus tenellus, Potamophylax goulandriourum, Oecetis notata, and Notidobia melanoptera. Even though this article is a result of a limited sampling effort, it increases the number of Trichoptera taxa recorded for the Republic of Kosovo to 131. PMID:25434031

  15. Bacterial diversity of polluted surface sediments in the northern Adriatic Sea.

    PubMed

    Korlević, Marino; Zucko, Jurica; Dragić, Mirjana Najdek; Blažina, Maria; Pustijanac, Emina; Zeljko, Tanja Vojvoda; Gacesa, Ranko; Baranasic, Damir; Starcevic, Antonio; Diminic, Janko; Long, Paul F; Cullum, John; Hranueli, Daslav; Orlić, Sandi

    2015-05-01

    Samples were collected from sea sediments at seven sites in the northern Adriatic Sea that included six sites next to industrial complexes and one from a tourist site (recreational beach). The samples were assayed for alkanes and polycyclic aromatic hydrocarbons. The composition of the hydrocarbon samples suggested that industrial pollution was present in most cases. A sample from one site was also grown aerobically under crude oil enrichment in order to evaluate the response of indigenous bacterial populations to crude oil exposure. Analysis of 16S rRNA gene sequences showed varying microbial biodiversity depending on the level of pollution--ranging from low (200 detected genera) to high (1000+ genera) biodiversity, with lowest biodiversity observed in polluted samples. This indicated that there was considerable biodiversity in all sediment samples but it was severely restricted after exposure to crude oil selection pressure. Phylogenetic analysis of putative alkB genes showed high evolutionary diversity of the enzymes in the samples and suggested great potential for bioremediation and bioprospecting. The first systematic analysis of bacterial communities from sediments of the northern Adriatic Sea is presented, and it will provide a baseline assessment that may serve as a reference point for ecosystem changes and hydrocarbon degrading potential--a potential that could soon gain importance due to plans for oil exploitation in the area. PMID:25857844

  16. An algorithm for the detection of the white-tide ('mucilage') phenomenon in the Adriatic Sea using AVHRR data

    SciTech Connect

    Tassan, S. )

    1993-06-01

    An algorithm using AVHRR data has been set up for the detection of a white tide consisting of algae secretion ('mucilage'), an event occurring in the Adriatic Sea under particular meteorological conditions. The algorithm, which includes an ad hoc procedure for cloud masking, has been tested with reference to the mucilage map obtained from the analysis of contemporary Thematic Mapper data, as well as by comparing consecutive AVHRR scenes. The main features of the exceptional mucilage phenomenon that took place in the northern basin of the Adriatic Sea in summer 1989 are shown by a time series of maps.

  17. Morbillivirus and Pilot Whale Deaths, Mediterranean Sea

    PubMed Central

    Esperón, Fernando; Herraéz, Pedro; de los Monteros, Antonio Espinosa; Clavel, Cristina; Bernabé, Antonio; Sánchez-Vizcaino, J. Manuel; Verborgh, Philippe; DeStephanis, Renaud; Toledano, Francisco; Bayón, Alejandro

    2008-01-01

    An outbreak of a lethal morbillivirus infection of long-finned pilot whales occurred in the Mediterranean Sea from the end of October 2006 through April 2007. Sequence analysis of a 426-bp conserved fragment of the morbillivirus phosphoprotein gene indicates that the virus is more closely related to dolphin morbillivirus than to pilot whale morbillivirus. PMID:18439363

  18. Organochlorine contaminants in tissues of common bottlenose dolphins Tursiops truncatus from the northeastern part of the Adriatic Sea.

    PubMed

    Romanić, S Herceg; Holcer, D; Lazar, B; Klinčić, D; Mackelworth, P; Fortuna, C M

    2014-09-01

    Levels of 24 organochlorine compounds, including toxic mono-ortho PCB congeners, were determined in the organs and tissues (blubber, kidney, lung, muscle, liver, heart) of 13 common bottlenose dolphins (Tursiops truncatus) stranded between 2000 and 2005 in the northern part of the Croatian territorial waters of the Adriatic Sea. Polychlorinated biphenyls (PCBs) were found at higher concentrations in comparison with organochlorine pesticides (OCPs) in all of the analyzed tissues. Sums of six indicator congeners (Σ6PCB) constituted around 50% of the total PCB amount, while PCB-153 and PCB-138 were found to have the highest concentrations. Among the seven investigated OCPs, p,p'-DDE was found at the highest concentrations. In blubber, mean values of 22,048 and 11,310ngg(-1) wet weight were determined for ΣPCB and ΣDDT, respectively. Much lower concentrations were found in muscle samples, followed by similar concentrations in kidneys, liver and heart, while the lowest levels of organochlorine contaminants were found in lungs. The results indicate that p,p'-DDT is still being introduced in the Mediterranean region. PCB concentrations are among the highest found in this region and toxicological assessments indicate that the health of this specie is at high risk. PMID:25151654

  19. Regional approach to modeling the transport of floating plastic debris in the Adriatic Sea.

    PubMed

    Liubartseva, S; Coppini, G; Lecci, R; Creti, S

    2016-02-15

    Sea surface concentrations of plastics and their fluxes onto coastlines are simulated over 2009-2015. Calculations incorporate combinations of terrestrial and maritime litter inputs, the Lagrangian model MEDSLIK-II forced by AFS ocean current simulations, and ECMWF wind analyses. With a relatively short particle half-life of 43.7 days, the Adriatic Sea is defined as a highly dissipative basin where the shoreline is, by construction, the main sink of floating debris. Our model results show that the coastline of the Po Delta receives a plastic flux of approximately 70 kg(km day)(-1). The most polluted sea surface area (>10 g km(-2) floating debris) is represented by an elongated band shifted to the Italian coastline and narrowed from northwest to southeast. Evident seasonality is found in the calculated plastic concentration fields and the coastline fluxes. Complex source-receptor relationships among the basin's subregions are quantified in impact matrices. PMID:26774440

  20. Sedimentological, biogeochemical and mineralogical facies of Northern and Central Western Adriatic Sea

    NASA Astrophysics Data System (ADS)

    Spagnoli, Federico; Dinelli, Enrico; Giordano, Patrizia; Marcaccio, Marco; Zaffagnini, Fabio; Frascari, Franca

    2014-11-01

    The aim of this work was to identify sedimentary facies, i.e. facies having similar biogeochemical, mineralogical and sedimentological properties, in present and recent fine sediments of the Northern and Central Adriatic Sea with their spatial and temporal variations. Further aims were to identify the transportation, dispersion and sedimentation processes and provenance areas of sediments belonging to the facies. A Q-mode factor analysis of mineralogical, granulometric, geochemical (major and trace elements) and biochemical (organic carbon and total nitrogen) properties of surficial and sub-surficial sediments sampled in the PRISMA 1 Project has been used to identify the sedimentary facies. On the whole, four facies were identified: 1) Padanic Facies, made up of fine siliciclastic sediments which reach the Adriatic Sea mainly from the Po River and are distributed by the Adriatic hydrodynamic in a parallel belt off the Italian coast. Southward, this facies gradually mixes with sediments from the Apennine rivers and with biogenic autochthonous particulate; 2) Dolomitic Facies, made up of dolomitic sediments coming from the eastern Alps. This facies is predominant north of the Po River outfalls and it mixes with Padanic Facies sediments in front of the Po River delta; 3) Mn-carbonate Facies, made up of very fine sediments, rich in coccolithophores and secondary Mn-oxy-hydroxides resulting from the reworking of surficial fine sediments in shallow areas and subsequent deposition in deeper areas; 4) Residual Facies, made up of coarse siliciclastic sediments and heavy minerals resulting from the action of waves and coastal currents; this facies is present mainly in inshore areas. The zoning of the facies, resulting from this study, will make possible the identification, through further investigation, on a greater scale, of more accurate facies borders and the recognition of sub-facies, resulting from secondary or weaker biogeochemical processes.

  1. Contemporary genetic structure and postglacial demographic history of the black scorpionfish, Scorpaena porcus, in the Mediterranean and the Black Seas.

    PubMed

    Boissin, E; Micu, D; Janczyszyn-Le Goff, M; Neglia, V; Bat, L; Todorova, V; Panayotova, M; Kruschel, C; Macic, V; Milchakova, N; Keskin, Ç; Anastasopoulou, A; Nasto, I; Zane, L; Planes, S

    2016-05-01

    Understanding the distribution of genetic diversity in the light of past demographic events linked with climatic shifts will help to forecast evolutionary trajectories of ecosystems within the current context of climate change. In this study, mitochondrial sequences and microsatellite loci were analysed using traditional population genetic approaches together with Bayesian dating and the more recent approximate Bayesian computation scenario testing. The genetic structure and demographic history of a commercial fish, the black scorpionfish, Scorpaena porcus, was investigated throughout the Mediterranean and Black Seas. The results suggest that the species recently underwent population expansions, in both seas, likely concomitant with the warming period following the Last Glacial Maximum, 20 000 years ago. A weak contemporaneous genetic differentiation was identified between the Black Sea and the Mediterranean Sea. However, the genetic diversity was similar for populations of the two seas, suggesting a high number of colonizers entered the Black Sea during the interglacial period and/or the presence of a refugial population in the Black Sea during the glacial period. Finally, within seas, an east/west genetic differentiation in the Adriatic seems to prevail, whereas the Black Sea does not show any structured spatial genetic pattern of its population. Overall, these results suggest that the Black Sea is not that isolated from the Mediterranean, and both seas revealed similar evolutionary patterns related to climate change and changes in sea level. PMID:26989881

  2. Abyssal and deep circulation in the Eastern Mediterranean Sea (Ionian Sea)

    NASA Astrophysics Data System (ADS)

    Artale, Vincenzo; Bensi, Manuel; Falcini, Federico; Marullo, Salvatore; Rubino, Angelo

    2016-04-01

    In the mid-1990s, experimental evidences on the Eastern Mediterranean Transient (EMT) were presented and it was shown that the Mediterranean abyssal circulation is not in a steady state but can be subjected to episodic sudden changes (Roether et al., 1996). In the last 10 years the Ionian Sea, the central and deepest part of the Mediterranean Sea, was subjected to relevant scientific interests from a theoretical and experimental point of view. Among these, there is the discovery of the BiOS (Bimodal Oscillating System), one new mechanism that drives a periodic (almost decadal) redistribution of surface and subsurface waters in the Eastern Mediterranean, with considerable feedbacks in the variability of the deep-water formation both in the southern Adriatic and in the Levantine and Aegean sub-basins (Gačić et al., 2010). In the Ionian Sea, numerous recent observational campaigns have been conducted to investigate the behaviour of deep and abyssal waters, at depths between 2000-4000m that are comparable to the mean global ocean depth (Rubino and Hainbucher, 2007; Bensi et al., 2013). There, advection, diffusion and vertical stability of the water masses can assume an important role on the internal quasi-periodical variability, creating the preconditions for catastrophic events such as the EMT or reversals of the Ionian circulation (Pisacane et al., 2006). Since there are no significant deep heat sources in the world ocean, waters that fill the deep ocean can only return to the sea surface as a result of downward mixing of heat from the sea surface to the bottom and vice versa and this occurs through eddy diffusion. Along our presentation, mainly through the analysis of the deepest CTD casts taken from 2009 to 2011 in the eastern basins and in particular in the Ionian Sea, we will show a significant change in the deep thermohaline structure (including its biogeochemical and hydrological characteristics), giving an indication on the time scale of the renewal of deep

  3. Acidification of the Mediterranean Sea during the 21st century

    NASA Astrophysics Data System (ADS)

    Le Vu, Briac; Palmieri, Julien; Orr, James C.; Dutay, Jean Claude; Sevault, Florence

    2014-05-01

    , the future simulation predicts a reduction in surface pH (acidification) of the Mediterranean Sea between 2000 and 2050 of 0.1 units (total scale); however, that change is not identical everywhere. It is 0.02 units less where there is strong mixing with deep waters (Gulf of Lyon, Rhodes Gyre and south Adriatic Sea), which are impoverished in anthropogenic CO2. It is also less, but only by 0.005 units, in regions most affected by incoming water from the Atlantic Ocean (near the Strait of Gibralter). Conversely, acidification is more intense (the magnitude of the pH change is larger) by 0.03 units in coastal areas such as the Dardanelles Strait, and near outflow from the Rhone and Po rivers, whose waters are more acidic and less able to buffer the increase in CO2. The simulated changes in surface pH in the Mediterranean Sea are almost entirely driven only by the direct geochemical effect from rising atmospheric CO2.

  4. Investigation on tsunami effects in the central Adriatic Sea during the last century - a contribution

    NASA Astrophysics Data System (ADS)

    Maramai, A.; Graziani, L.; Tinti, S.

    2007-01-01

    In this work we present the result of a study aimed at examining the Italian earthquake sequences that occurred in the area of the central Adriatic sea with the purpose of understanding whether some of them were accompanied by tsunami effects. The motivation for this research was the update and enrichment of the Italian Tsunami Catalogue. The result was that evidence was found for two new cases of earthquake-induced tsunamis: these are the August 1916 Rimini and the October 1930 Ancona events. The bulk of the present research consisted in collecting all the available data on the earthquakes that affected the selected area in the past century and in identifying those potentially capable of generating tsunamis. During the study all the available material was gathered, which includes specific monographs and scientific papers, articles available in contemporary chronicles and in local and national newspapers. The final result of this research will improve our knowledge of the tsunamigenic activity of the central Adriatic sea and contribute to the assessment of the tsunami hazard and risk along these coasts, that especially in the peak season form one of the most densely populated areas of the Italian peninsula with flat and large beaches and water front resorts crowded of tourists.

  5. Large-scale distribution and production of bacterioplankton in the Adriatic Sea

    NASA Astrophysics Data System (ADS)

    Gallina, Alessandra A.; Celussi, Mauro; Del Negro, Paola

    2011-08-01

    Two oceanographic cruises encompassing the whole Adriatic Sea were carried out during February and October 2008. Selected stations were sampled at several depths to determine total prokaryotes and picocyanobacteria abundance using epifluorescence microscopy, and to estimate prokaryotic carbon production by 3H-leucine incorporation. Biological data were related to physical parameters including temperature, salinity and fluorescence, and an attempt to associate bacterial dynamics to water mass characteristics was performed. In both seasons prokaryotic distribution and production showed a decreasing latitudinal gradient likely dependent on riverine inputs highlighted by a strong negative correlation with salinity ( P < 0.001). A vertical gradient with higher cell numbers at the surface and lower values at the bottom layer was also always detected. In the southern basin in February, however, picocyanobacteria were retrieved also in deep waters, probably linked to higher nutrient loads carried by the Levantine Intermediate Waters and/or the deep water ventilation known to occur in this area. From an oceanographic point of view, we sampled within four different water types, but no relationship between these water types and bacterioplankton abundances was found. The present work contributes to the acquisition of a more holistic overview of prokaryotic distribution and production in the Adriatic Sea, both on a spatial and temporal scale.

  6. Zooplankton community and hydrographical properties of the Neretva Channel (eastern Adriatic Sea)

    NASA Astrophysics Data System (ADS)

    Vidjak, Olja; Bojanić, Natalia; Kušpilić, Grozdan; Ninčević Gladan, Živana; Tičina, Vjekoslav

    2007-12-01

    Temporal and spatial variability of micro and mesozooplankton was studied in 1998 and 1999 at four stations in the Neretva Channel area influenced by the Neretva river and the open waters of the south Adriatic Sea. The area is orthophosphate limited, but an excessive accumulation of land derived nitrogen is prevented by phytoplankton uptake and the general circulation pattern. Microzooplankton was dominated by ciliates, with average abundances comparable to other Adriatic channel areas (122 543 ind. l-1). Non-loricate ciliates (NLC) generally peaked in the warmer periods, but a winter increase was evident towards the inner part of the channel. Tintinnid abundances generally increased in autumn. A significant relationship with temperature was not recorded for either protozoan group. An inverse relationship between NLC and salinity might be indirectly caused by their preference for the food abundant surface layer. Mesozooplankton was dominated by copepods, with distinct summer maxima throughout the area and pronounced winter maxima of >10,000 ind. m-3 at the inner stations. The community was predominantly neritic but the open sea waters were important in structuring the mesozooplankton assemblage at all stations during the autumn winter period. Although temperature regulated the seasonal dynamics of most metazoans and the species succession in the copepod community, small omnivorous copepods ( Oncaea media complex, Oithona nana and Euterpina acutifrons) dominated regardless of the season. A trophic link between copepods and ciliates was evident in winter during low phytoplankton biomass.

  7. Survey of Anisakis sp. and Hysterothylacium sp. in sardines and anchovies from the North Adriatic Sea.

    PubMed

    Cavallero, S; Magnabosco, C; Civettini, M; Boffo, L; Mingarelli, G; Buratti, P; Giovanardi, O; Fortuna, C M; Arcangeli, G

    2015-05-01

    The occurrence of larval Anisakidae and Raphidascarididae in anchovies and sardines from the North Adriatic Sea has been estimated. Anisakis pegreffii and Hysterothylacium aduncum were reported, with low prevalence values. In brief, a total amount of 7650 fish specimens collected between September 2011 and 2012 were analysed using three different inspection analyses: a visual inspection of the coelomic cavity, an examination of the viscera exploiting the positive hydro-tropism of the larvae (modified Baermann technique) and enzymatic digestion of muscular tissue pools. Low level of infestation was reported for Anisakis sp. in both in anchovies and sardines, while higher values were reported for Hysterothylacium sp. Subsamples of nematodes collected were characterized at species level using the molecular diagnostic key based on ITS nuclear ribosomal region, and A. pegreffii and H. aduncum were identified. The low prevalence of Anisakis sp. in sardines and anchovies from the North Adriatic Sea could be related to the peculiar distribution of cetaceans and carnivorous zooplankton in the investigated region and could be used as a potential tag to define oily fishes from this specific fishing area as at low-risk for anisakiasis. PMID:25662709

  8. Plastic Accumulation in the Mediterranean Sea

    PubMed Central

    Cózar, Andrés; Sanz-Martín, Marina; Martí, Elisa; González-Gordillo, J. Ignacio; Ubeda, Bárbara; Gálvez, José Á.; Irigoien, Xabier; Duarte, Carlos M.

    2015-01-01

    Concentrations of floating plastic were measured throughout the Mediterranean Sea to assess whether this basin can be regarded as a great accumulation region of plastic debris. We found that the average density of plastic (1 item per 4 m2), as well as its frequency of occurrence (100% of the sites sampled), are comparable to the accumulation zones described for the five subtropical ocean gyres. Plastic debris in the Mediterranean surface waters was dominated by millimeter-sized fragments, but showed a higher proportion of large plastic objects than that present in oceanic gyres, reflecting the closer connection with pollution sources. The accumulation of floating plastic in the Mediterranean Sea (between 1,000 and 3,000 tons) is likely related to the high human pressure together with the hydrodynamics of this semi-enclosed basin, with outflow mainly occurring through a deep water layer. Given the biological richness and concentration of economic activities in the Mediterranean Sea, the affects of plastic pollution on marine and human life are expected to be particularly frequent in this plastic accumulation region. PMID:25831129

  9. Plastic accumulation in the Mediterranean sea.

    PubMed

    Cózar, Andrés; Sanz-Martín, Marina; Martí, Elisa; González-Gordillo, J Ignacio; Ubeda, Bárbara; Gálvez, José Á; Irigoien, Xabier; Duarte, Carlos M

    2015-01-01

    Concentrations of floating plastic were measured throughout the Mediterranean Sea to assess whether this basin can be regarded as a great accumulation region of plastic debris. We found that the average density of plastic (1 item per 4 m2), as well as its frequency of occurrence (100% of the sites sampled), are comparable to the accumulation zones described for the five subtropical ocean gyres. Plastic debris in the Mediterranean surface waters was dominated by millimeter-sized fragments, but showed a higher proportion of large plastic objects than that present in oceanic gyres, reflecting the closer connection with pollution sources. The accumulation of floating plastic in the Mediterranean Sea (between 1,000 and 3,000 tons) is likely related to the high human pressure together with the hydrodynamics of this semi-enclosed basin, with outflow mainly occurring through a deep water layer. Given the biological richness and concentration of economic activities in the Mediterranean Sea, the affects of plastic pollution on marine and human life are expected to be particularly frequent in this plastic accumulation region. PMID:25831129

  10. On the dense water cascading in the Southern Adriatic Sea during 2012: Setup of a Rapid Environmental Assessment

    NASA Astrophysics Data System (ADS)

    Langone, Leonardo

    2013-04-01

    In the North Adriatic, Dense Shelf Water (DSW) forms during cold and dry winters by cooling and evaporation. DSW spreads southward along the western shelf reaching the southern Adriatic basin (1200 m deep) after 1-2 months, where sinks through cascading events. In February 2012, a large Siberian High caused blocking of the Atlantic flow and a westward flow of dry and cold air masses from eastern Russia toward Europe. The North Adriatic experienced a cold spell with large decrease of surface temperature (3° -6° C) associated to severe cold and dry Bora wind. The result was the formation of extremely dense shelf water, further made possible by the very limited discharge of the Po river in the preceding autumn. As contribution to the Italian research programme RITMARE (Italian Research for the Sea), CNR-ISMAR set up a Rapid Environmental Assessment (REA) experiment to study the occurrence, amount, timing and properties of the newly formed DSW. Setting up REA strategies is crucial for several scientific and practical reasons: (i) capturing extreme events to improve our understanding of natural systems in a global-change scenario; (ii) to evaluate their impact on marine systems and the biota; (iii) to address issues related to fluctuating fish stocks as well as (iv) C export and sequestration in the deep sea. The experiment was designed with an integrated approach, including modeling simulations, mooring deployments and quick-response oceanographic cruises. Based on numerical model ensemble, the arrival time of the DSW at the Gargano Cape was forecasted likely starting after March 15, 2012, thus moorings were deployed few days before. Five moorings were deployed in sites selected on the basis of modelling predictions and geology-driven inferences defining areas where the passage of dense shelf water is most likely to occur. Moorings were equipped with down-looking ADCPs, automatic sediment traps, temperature loggers, recorders of temperature, conductivity and

  11. Sea/land breeze climatological characteristics along the northern Croatian Adriatic coast

    NASA Astrophysics Data System (ADS)

    Prtenjak, M. Telišman; Grisogono, B.

    2007-11-01

    Climatological characteristics along the northern Croatian Adriatic coast have been examined for nine meteorological stations for the summertime sea/land breeze circulation. The stations considered are Pula-airport, Opatija, Rijeka, Senj, Malinska, Rijeka-airport, Mali Lošinj, Rab and Zadar. The hourly surface measurements at each station from June to September for the period 1991 2004 as well as the radiosoundings in Zadar (from 2002 to 2004) were used for the analysis. A dataset with the sea/land breeze days was formed according to the several criteria. The mean daily maxima of both air and sea surface temperatures were more influenced by the large scale disturbances toward north (e.g. in Rijeka or Opatija) compared to the values for e.g. Zadar. Furthermore, the influence of the large scale disturbances diminished toward the south concerning the sea land temperature difference only at the stations placed at Rijeka Bay and Velebit channel. The strongest sea breeze was found at Pula-airport and the most frequent ones at Opatija and Zadar. At Senj the rarest, the weakest and the shortest sea breeze was observed. The climatological records of wind speed and air-sea temperature difference (Δ T) showed for Opatija, Malinska and Zadar that the maximum measured wind speed is around 4.5 °C confirming the nonlinear relationship between the sea breeze speeds and the Δ T during the day. At most stations, the clockwise rotation of the hodographs prevails which is typical for the Northern hemisphere due to Coriolis force, with the exception at Senj and Malinska. While the hodographs for Pula, Rijeka-airport and Mali Lošinj display a later onset of the prevailing sea breeze because of the interaction among several sea breeze circulations, the results for Opatija, Zadar and Senj show considerably distorted hodographs because of the nearby channeling of the air flow.

  12. Humic acids contribution to sedimentary organic matter on a shallow continental shelf (northern Adriatic Sea)

    NASA Astrophysics Data System (ADS)

    Giani, M.; Rampazzo, F.; Berto, D.

    2010-12-01

    The shallow northern Adriatic Sea receives large river runoff, predominantly from the Po River, which is the main allochthonous source of nutrients and organic matter. The origin and quality of organic matter deposited in the sediments can influence the degradation processes and oxygen consumption in the bottom waters as well as the fate of many pollutants. Therefore the humic acids (HA) were quantified in surface and sub-surface sediments collected in an area of the north-western Adriatic platform south of Po River. HA showed to have a relevant contribution to sedimentary organic matter. HA content in sediments were positively correlated with the organic carbon concentration and negatively with redox potential and pH, particularly in sub-surface reduced sediments, suggesting their important role in the diagenetic processes taking place in anoxic conditions. Elemental composition of HA extracted from surface and sub-surface sediments showed a wide range of variation of the C org/N ratios which could be due to a mixed (terrestrial and marine) origin and/or an elevated bacteria degradation of nitrogen during diagenesis processes in sediments. The spectroscopic ratios A 2/A 4 and A 4/A 6 of HA confirmed a mixed origin with a high degree of condensation of the HA extracted from sediments.

  13. Recent changes in the marine ecosystems of the northern Adriatic Sea

    NASA Astrophysics Data System (ADS)

    Giani, Michele; Djakovac, Tamara; Degobbis, Danilo; Cozzi, Stefano; Solidoro, Cosimo; Umani, Serena Fonda

    2012-12-01

    This review of studies on long term series on river discharges, oceanographic features, plankton, fish and benthic compartments, collected since the 1970s revealed significant changes of mechanisms and trophic structures in the northern Adriatic ecosystems. A gradual increase of eutrophication pressure occurred during the 1970s until the mid 1980s, followed by a reversal of the trend, particularly marked in the 2000s. This trend was ascribed to the combination of a reduction of the anthropogenic impact, mainly due to a substantial decrease of the phosphorus loads, and of climatic modifications, resulting in a decline of atmospheric precipitations and, consequently, of the runoff in the northern Adriatic Sea. Significant decreases of the phytoplankton abundances were observed after the mid 1980s, concurrently with changes in the species composition of the communities, with an evident shift toward smaller cells or organism sizes. Moreover, changes in the zooplankton community were also observed. A decrease of demersal fishes, top predators and small pelagic fishes was ascribed to both overfishing and a demise of eutrophication. Macrozoobenthic communities slowly recovered in the last two decades after the anoxia events of the 1970s and 1980s. An increasing number of non-autochthonous species has been recorded in the last decades moreover the increasing seawater temperature facilitated the spreading of thermophilic species.

  14. Tephrochronology of core PRAD 1-2 from the Adriatic Sea: insights into Italian explosive volcanism for the period 200-80 ka

    NASA Astrophysics Data System (ADS)

    Bourne, A. J.; Albert, P. G.; Matthews, I. P.; Trincardi, F.; Wulf, S.; Asioli, A.; Blockley, S. P. E.; Keller, J.; Lowe, J. J.

    2015-05-01

    Core PRAD 1-2, located on the western flank of the Mid-Adriatic Deep, was investigated for tephra content within the part of the sequence assigned on biostratigraphic and sapropel-layer stratigraphy to MIS 5 and 6 (ca. 80-200 ka BP). A total of 11 discrete tephra layers are identified, 8 visible and 3 cryptotephra layers. 235 geochemical measurements obtained from individual glass shards using WDS-EPMA enabled 8 of the 11 tephras to be correlated to known eruption events, 5 of which are represented in the Lago Grande di Monticchio (LGdM) regional tephra archive sequence. Three of these layers are recognised ultra-distally for the first time, extending their known distributions approximately 210 km further north. The results provide an independent basis for establishing an age-depth profile for the MIS 5-6 interval in the PRAD 1-2 marine record. This approach allowed age estimates to be interpolated for the tephra layers that could not be correlated to known events. It also provides an independent test of, and support for, the broad synchroneity of sapropel-equivalent (S-E) events in the Adriatic Sea with the better-developed sapropel layers of the eastern Mediterranean, proposed by Piva et al. (2008a).

  15. Microbial processes and organic priority substances in marine coastal sediments (Adriatic Sea, Italy)

    NASA Astrophysics Data System (ADS)

    Zoppini, Annamaria; Ademollo, Nicoletta; Amalfitano, Stefano; Dellisanti, Walter; Lungarini, Silvia; Miserocchi, Stefano; Patrolecco, Luisa; Langone, Leonardo

    2015-04-01

    PERSEUS EU FP7 Project aims to identify the interacting patterns of natural and human-derived pressures to assess their impact on marine ecosystems and, using the objectives and principles of the Marine Strategy Framework Directive (MSFD) as a vehicle, to design an effective and innovative research governance framework based on sound scientific knowledge. In the frame of this Project (subtask 1.3.3 ADREX: Adriatic and Ionian Seas Experiment), monitoring surveys were conducted in the Adriatic Sea (Italy) in order to study the variation of structural and functional characteristics of native bacterial communities and the occurrence of selected classes of organic priority substances in sediments. The study area represents a good natural laboratory sensitive to climate variability and human pressure, owing to the semi-enclosed nature of the Adriatic Sea and to the increasing trend of human activities in the coastal regions. During the cruise ADRI-13 (November 2013) and ADRI-14 (October 2014) we sampled several coastal sites from the mouth of the Po River to the Otranto strait. Surface sediments were collected in all areas, while sediment cores were sampled in selected sites. Microbes associated with marine sediments play an important role in the C-flux being responsible for the transformation of organic detritus (autochthonous and allochthonous) into biomass. The sediment bacterial abundance was determined by epifluorescence microscopy and the rate of bacterial carbon production by measuring the 3H-leucine uptake rates. The community respiration rate was estimated by the measurement of the electron transport system (ETS) activity. The sediment contamination level was determined by measuring the concentration of contaminants included in the list of organic priority substances: PAHs, bisphenol A (BPA), alkylphenols (APs). The extraction/clean-up of PAHs, BPA and APs was performed by ultrasonic bath with the appropriate solvents, followed by analytical determination with

  16. ROOT PLASTICITY TO NUTRITIONAL STRESS IN MEDITERRANEAN SEA BEET

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Knowledge of root adaptive responses to nutritional stress is required to improve yield stability of sugarbeet. The aim of this research was a comparative study of the root morpho-physiological plasticity among two sea beet populations collected on poor- and nutrient-rich habitats of the Adriatic co...

  17. Performance analysis of coupled and uncoupled hydrodynamic and wave models in the northern Adriatic Sea

    NASA Astrophysics Data System (ADS)

    Busca, Claudia; Coluccelli, Alessandro; Valentini, Andrea; Benetazzo, Alvise; Bonaldo, Davide; Bortoluzzi, Giovanni; Carniel, Sandro; Falcieri, Francesco; Paccagnella, Tiziana; Ravaioli, Mariangela; Riminucci, Francesco; Sclavo, Mauro; Russo, Aniello

    2014-05-01

    The complex dynamics of the Adriatic Sea are the result of geographical position, orography and bathymetry, as well as rivers discharge and meteorological conditions that influence, more strongly, the shallow northern part. Such complexity requires a constant monitoring of marine conditions in order to support several activities (marine resources management, naval operations, emergency management, shipping, tourism, as well as scientific ones). Platforms, buoys and mooring located in Adriatic Sea supply almost continuously real time punctual information, which can be spatially extended, with some limitations, by drifters and remote sensing. Operational forecasting systems represent valid tools to provide a complete tridimensional coverage of the area, with a high spatial and temporal resolution. The Hydro-Meteo-Clima Service of the Emilia-Romagna Environmental Agency (ARPA-SIMC, Bologna, Italy) and the Dept. of Life and Environmental Sciences of Università Politecnica delle Marche (DISVA-UNIVPM, Ancona, Italy), in collaboration with the Institute of Marine Science of the National Research Council (ISMAR-CNR, Italy) operationally run several wave and hydrodynamic models on the Adriatic Sea. The main implementations are based on the Regional Ocean Modeling System (ROMS), the wave model Simulating WAves Nearshore (SWAN), and the coupling of the former two models in the Coupled Ocean-Atmosphere-Wave-Sediment Transport (COAWST) system. Horizontal resolutions of the different systems range from the 2 km of AdriaROMS to the 0.5 km of the recently implemented northern Adriatic COAWST. Forecasts are produced every day for the subsequent 72 hour with hourly resolution. All the systems compute the fluxes exchanged through the interface with the atmosphere from the numerical weather prediction system named COSMO-I7, an implementation for Italy of the Consortium for Small-scale Modeling (COSMO) model, at 7 km horizontal resolution. Considering the several operational

  18. Climate change effects on environment (marine, atmospheric and terrestrial) and human perception in an Italian Region (Marche) and the nearby northern Adriatic Sea.

    NASA Astrophysics Data System (ADS)

    Appiotti, F.; Krzelj, M.; Marincioni, F.; Russo, A.

    2012-04-01

    An integrated analysis of recent climate change, including atmosphere, sea and land, as well as some of the impacts on society, has been conducted on the Marche Region in central Italy and the northern portion of the Adriatic Sea. The Marche Region is one of the 20 administrative divisions of Italy, located at a latitude approximately 43° North, with a total surface area of 9,366 km2 and 1,565,000 residents. The northern Adriatic Sea is the northernmost area of the Mediterranean Sea, and it has peculiar relevance for several aspects (environment, tourism, fisheries, economy). The collected environmental data included meteorological stations (daily maximum and minimum air temperature, daily precipitation), oceanographic stations (sea temperature, salinity, dissolved oxygen, nutrient salts concentration, chlorophyll) and river flows, over the last 50 years. The collected social data include 800 questionnaires and interviews carried out on selected samples of residents, decision-makers and emergency managers. These questionnaires and interviews aimed at highlighting the perception of climate change risks. The trend analysis of air temperature and precipitation data detailed an overall temperature increase in all seasons and rainfall decreases in Winter, Spring and Summer with Autumn increases, influencing river flow changes. Marine data showed a relevant warming of the water column in the period after 1990 in comparison with the previous period, particularly in the cold season. Surface salinity increased in Spring and Summer and strongly decreased in Autumn and Winter (according with the precipitation and river flow changes). These last mentioned changes, combined with anthropogenic effects, also influenced the marine ecosystems, with changes of nutrient salts, chlorophyll and dissolved oxygen. Changes in nutrient discharge from rivers influenced the average marine chlorophyll concentration reduction and the consequent average reduction of warm season hypoxic

  19. Bioaccumulation of Arsenic Species in Rays from the Northern Adriatic Sea

    PubMed Central

    Šlejkovec, Zdenka; Stajnko, Anja; Falnoga, Ingrid; Lipej, Lovrenc; Mazej, Darja; Horvat, Milena; Faganeli, Jadran

    2014-01-01

    The difference in arsenic concentration and speciation between benthic (Pteromylaeus bovinus, Myliobatis aquila) and pelagic rays (Pteroplatytrygon violacea) from the northern Adriatic Sea (Gulf of Trieste) in relation to their size (age) was investigated. High arsenic concentrations were found in both groups with tendency of more efficient arsenic accumulation in benthic species, particularly in muscle (32.4 to 362 µg·g−1 of total arsenic). This was attributed to species differences in arsenic access, uptake and retention. In liver most arsenic was present in a form of arsenobetaine, dimethylarsinic acid and arsenoipids, whereas in muscle mainly arsenobetaine was found. The good correlations between total arsenic/arsenobetaine and size reflect the importance of accumulation of arsenobetaine with age. Arsenobetaine is an analogue of glycine betaine, a known osmoregulator in marine animals and both are very abundant in mussels, representing an important source of food for benthic species P. bovinus and M. aquila. PMID:25470025

  20. STS-56 ESC Earth observation of Korcula and Peljesac islands in Adriatic Sea

    NASA Technical Reports Server (NTRS)

    1993-01-01

    STS-56 electronic still camera (ESC) Earth observation image is of two small islands (Korcula and Peljesac) in the Adriatic Sea, southwest of Sarajevo. The scene was photographed during Discovery's, Orbiter Vehicle (OV) 103's, 33rd orbit with a 300mm lens on the Hand-held, Earth-oriented, Real-time, Cooperative, User-friendly, Location-targeting and Environmental System (HERCULES). HERCULES is a device that makes it simple for shuttle crewmembers to take pictures of Earth as they merely point a modified 35mm camera and shoot any interesting feature, whose latitude and longitude are automatically determined in real-time. Center coordinates of this frame are 42.9 degrees north latitude and 17.2 degrees east longitude. The camera was in shutter priority mode with a 1/500-second shutter speed and -2/3 exposure compensation. Digital file name is ESC03036.IMG.

  1. Spatial pattern and weight of seabed marine litter in the northern and central Adriatic Sea.

    PubMed

    Strafella, P; Fabi, G; Spagnolo, A; Grati, F; Polidori, P; Punzo, E; Fortibuoni, T; Marceta, B; Raicevich, S; Cvitkovic, I; Despalatovic, M; Scarcella, G

    2015-02-15

    The present study analyzes spatial distribution and typology of marine litter on the seabed in the FAO Geographical Sub-Area 17 (northern and central Adriatic Sea). Two surveys were conducted during fall 2011 and 2012 and 67 stations were sampled each year. Litter items were collected using the "rapido" trawl, a modified beam trawl commonly used by the Italian fishermen to catch flat fish and other benthic species. Marine litter in the catches was sorted and classified in 6 major categories (plastic, metal, glass, rubber, wood, other). Plastic litter was further subdivided in 3 sub-categories based on its source: fishing nets, aquaculture nets and other. Plastic was dominant in terms of weight followed by metal and other categories. The highest concentration of litter was found close to the coast likely as a consequence of high coastal urbanization, river inflow and extensive navigation associated with the morphological and hydrological features of the basin. PMID:25560999

  2. Harmful Algae Records in Venice Lagoon and in Po River Delta (Northern Adriatic Sea, Italy)

    PubMed Central

    Bilaničovà, Dagmar; Marcomini, Antonio

    2014-01-01

    A detailed review of harmful algal blooms (HAB) in northern Adriatic Sea lagoons (Po River Delta and Venice lagoon) is presented to provide “updated reference conditions” for future research and monitoring activities. In the study areas, the high mollusc production requires the necessity to identify better methods able to prevent risks for human health and socioeconomical interests. So, an integrated approach for the identification and quantification of algal toxins is presented by combining microscopy techniques with Liquid Chromatography coupled with High Resolution Time of Flight Mass Spectrometry (HPLC-HR-TOF-MS). The method efficiency was first tested on some samples from the mentioned coastal areas, where Dinophysis spp. occurred during summer in the sites directly affected by seawaters. Although cell abundance was always <200 cells/L, the presence of Pectenotoxin-2 (PTX2), detected by HPLC-HR-TOF-MS, indicated the potential release of detectable amounts of toxins even at low cell abundance. PMID:24683360

  3. Bathing water profile in the coastal belt of the province of Pescara (Italy, Central Adriatic Sea).

    PubMed

    Liberatore, Lolita; Murmura, Federica; Scarano, Antonio

    2015-06-15

    The quality of bathing water is fundamental, not only from an environmental point of view but also due to the economic importance of tourism. This paper examines the water profile in the coastal belt of the province of Pescara (Italy, Central Adriatic Sea) with reference to the microbiological parameters Escherichia coli and intestinal enterococci required by Directive 2006/07 of European Commission. The water quality of 15 coastal beaches was surveyed; data were produced from monitoring and controls made available by the Abruzzo Regional Environmental Prevention and Protection Agency (ARTA) and extracted and elaborated for the period of interest (2010-2013). Statistical analysis was used to confirm the aspects deduced from mean values of monitoring and control data for each stretch. The data highlight critical situations in various parts of the coast; these problems can be attributed to river pollution, mainly due to the malfunctioning of the treatment plants for urban wastewater. PMID:25934432

  4. Distribution patterns of carbon oxidation in the eastern Mediterranean Sea: Evidence of changes in the remineralization processes

    NASA Astrophysics Data System (ADS)

    La Ferla, Rosabruna; Azzaro, Maurizio; Civitarese, Giuseppe; Ribera D'Alcalã, Maurizio

    2003-09-01

    Deep remineralization patterns, as carbon dioxide production, were investigated in microplankton samples from several areas of eastern Mediterranean Sea. The respiration data, collected during six oceanographic surveys from 1993 through 1999, evidence biogeochemical peculiarities of the deep waters of Mediterranean as compared to the open ocean and allow drawing up an hypothesis on the possible impact of the Eastern Mediterranean Transient (EMT) on remineralization processes. The temporal trend of the oxidative processes in the basin is tightly coupled with the main features of the circulation pattern. In the Mediterranean Sea, the convective processes and the consequent advection of dense waters assume a relevant role in sustaining the amount of remineralization in the deep layers and appear to be more important than the sinking of particulate matter from the upper layers. Respiration in the deepest Mediterranean waters accounts for a greater percentage of the upper aphotic zone respiration (over 45%) than that found in the open oceans (below 21%). In addition, the increase in respiratory rates in only a few years in the Ionian Basin could represent a signal of the changes induced by the EMT, which replaced the Adriatic deepwater supply with waters of Aegean origin. The ecological change induced by the EMT, negligible in the photic layers of the eastern Mediterranean Sea, seems to concern the impact of the continental shelf pump by advection of younger, less-refractory organic matter utilizable by deep biota.

  5. Relationship between microbial communities and mercury species in the seawater of the Central Adriatic Sea

    NASA Astrophysics Data System (ADS)

    Zivkovic, Igor; Horvat, Milena; Kotnik, Joze; Fajon, Vesna; Solic, Mladen; Kanduc, Tjasa

    2016-04-01

    The structure of the microbial food web and its role in biogeochemical processes in marine ecosystems may vary noticeably and depend on environmental trophic status. Importance of picoplankton makes them an essential component for understanding the food web dynamics in marine systems. These small organisms dominate the photosynthetic biomass and primary production in oligotrophic waters like the Adriatic Sea. One of the hypotheses of research is that the factors that enable scavenging nutrients at low concentrations also promote accumulation of contaminants in the biomass of microorganisms. Biologically mediated reactions can transform mercury species and facilitate their entrance into the marine food web in which it bioaccumulates in the form of methylmercury (MeHg). In order to establish relationship between Hg and microbial species, we performed samplings in the Central Adriatic Sea. Samplings were conducted during oceanographic cruises aboard the research vessel Bios Dva from March 2014 to December 2015. Research was constrained to transect from the island of Vis to the Bay of Kastela. Non-filtered water samples were collected for determination of methylmercury (MeHg), total mercury (THg), dissolved gaseous mercury (DGM), and microbial species in Adriatic coastal and open waters. In the pristine environment of the island of Vis, THg concentrations are the lowest and range from 0.14-1.10 ng/L. Mercury contamination from chlor-alkali industrial waters in the Bay of Kastela is observed through the highest THg concentrations (up to 5.58 ng/L). DGM always shows higher values in more contaminated areas (31.8-351 pg/L) than in the pristine environment (22.1-245 pg/L). MeHg concentrations vary, but the highest values are usually found in the Bay of Kastela (up to 34.3 pg/L). Number of picoeukaryotes is the highest in the Bay of Kastela (0.44×106-31.8×106/L) which has been affected by industrial and civil effluents from the surrounding cities. The lowest number is

  6. Levels of polychlorinated biphenyls and organochlorine pesticides in some edible marine organisms from the Central Adriatic Sea.

    PubMed

    Perugini, M; Cavaliere, M; Giammarino, A; Mazzone, P; Olivieri, V; Amorena, M

    2004-11-01

    Concentrations of polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCs) were found in tissue of marine organisms such as Mediterranean mussel, Norway lobster, red mullet, common cuttle-fish, European flying squid, European anchovy, European pilchard and Atlantic mackerel, coming from two sites along the Abruzzo coast of the Adriatic Sea. Species were selected due to their habitat, trophic level, feeding behaviour and their use in the Italian diet. Mussels, filter feeder and sedentary organisms, were used in order to test water pollution whereas Norway lobster and red mullet (benthic fish) were used in order to test sediment pollution. The concentration of ?PCBs exceeded that of ?OCs in the samples analysed. The highest concentrations of ?PCBs (1415 ng/g lipid weight) and ?OCs (507 ng/g lipid weight) were found in pilchard while the lowest concentrations of the same pollutants were found in cephalopods. Our results have shown that species such as anchovy, pilchard and mackerel, were the most polluted due to their location at the last level of the trophic chain. All samples contained different concentrations of PCBs and among these, congeners 153 and 138 were the most representative. Among the OCs, except for the cuttle-fish, the highest concentrations were found for p,p(')-DDE and p,p(')-DDD that are metabolite of DDT. The prevailing DDE presence, compared to DDT (high DDE/DDT ratio), suggested that the biotransformation rate of pollutants was very efficacious in fish and above all in crustaceans. Results have also been interpreted in terms of geographical distribution and organisms' biological cycle. None of the samples analysed exceeded the tolerance limits established by the OCs Italian legislation. PMID:15331266

  7. A tri-modular model for the computation of the meteorological and oceanographic fields in the Adriatic Sea

    SciTech Connect

    Lionello, P.; Pernigotti, D.; Zampato, L.; Bergamasco, A.; Buzzi, A.; Malguzzi, P.

    1994-12-31

    The purpose of this research program is the construction of the modelling framework to describe and predict the development of the sea and of the atmosphere in the Adriatic region. There are two time scales that are considered: the medium range time scale of the weather-surge-oceanwave forecast and the interseasonal time scale of the thermohaline circulation in the Adriatic Sea. The phenomenology associated with the medium range is represented by the intense storms that take place in the Adriatic Sea, in spite of its relatively small extension, when the presence of a pressure minimum over Italy generates an intense Scirocco wind which, channeled by the mountain ridges surrounding the basin, blows along its whole length. Because of the long fetch, approximately 1,000 Km., this situation produces high ocean waves and the storm surge that is associated with the flooding of Venice. The interseasonal phenomenology is represented by the formation of dense water in the Northern part of the basin during winter. This is presumably caused by Bora, a strong South-Westerly wind, cold and dry, which produces cooling and evaporation in the shallow water coastal region of the Northern Adriatic. The complex orography surrounding the Adriatic and the short duration of this phenomena require a model framework capable of high space and time resolution on a limited area. This is the motivation for addressing these issues in a coupled model framework consisting of a limited area atmospheric circulation model, an ocean circulation model, and a ocean wave model with high resolution both in space and time.

  8. Marine litter on Mediterranean shores: Analysis of composition, spatial distribution and sources in north-western Adriatic beaches.

    PubMed

    Munari, Cristina; Corbau, Corinne; Simeoni, Umberto; Mistri, Michele

    2016-03-01

    Marine litter is one descriptor in the EU Marine Strategy Framework Directive (MSFD). This study provides the first account of an MSFD indicator (Trends in the amount of litter deposited on coastlines) for the north-western Adriatic. Five beaches were sampled in 2015. Plastic dominated in terms of abundance, followed by paper and other groups. The average density was 0.2 litter items m(-2), but at one beach it raised to 0.57 items m(-2). The major categories were cigarette butts, unrecognizable plastic pieces, bottle caps, and others. The majority of marine litter came from land-based sources: shoreline and recreational activities, smoke-related activities and dumping. Sea-based sources contributed for less. The abundance and distribution of litter seemed to be particularly influenced by beach users, reflecting inadequate disposal practices. The solution to these problems involves implementation and enforcement of local educational and management policies. PMID:26725754

  9. Identity of Squalius (Actinopterygii, Cyprinidae) from Istra Peninsula in Croatia (Adriatic Sea basin)

    PubMed Central

    Zupancic, Primoz; Mrakovcic, Milorad; Marcic, Zoran; Naseka, Alexander M.; Bogutskaya, Nina G.

    2010-01-01

    Abstract A chub of previously ambiguous identity from the Boljunscica and Pazincica rivers (south-eastern Istra Peninsula) was studied and compared with geographically close Squalius squalus, Squalius zrmanja, and Squalius janae recently described from the Dragonja River drainage in the Adriatic Sea basin in Slovenia. It was shown that the chub from the south-eastern Istra Peninsula differs from all know species of Squalius but one: Squalius janae. Three samples examined from Boljunscica and Pazincica rivers and Squalius janae from its type locality, Dragonja River, show the following characters typical for the latter species: a long head (the head length 27–32% SL); a pointed conical snout with a clearly projecting upper jaw; a long straight mouth cleft, the lower jaw length (39–45% HL) exceeding the caudal peduncle depth; a large eye; commonly 9? branched anal-fin rays; commonly 44 total vertebrae (24+20 or 25+19); bright silvery colouration, scales easily lost; iris, pectoral, pelvic and anal fin pigmentation with yellow shades. The data on the distribution of Squalius chubs in the northern Adriatic basin support the assumption that the range of Squalius janae is determined by the geology of the Trieste Flysch Basin and the Pazin Flysch Basin forming the base of the Istra Peninsula. The distribution pattern of this species does not support a simple model of fish dispersal and a complete connectivity within the whole Palaeo-Po historical drainage. Indeed, it indicates a disrupted surface palaeohydrography that was heavily fragmented by karstification in the whole Dinaric area. PMID:21594132

  10. Eutrophication in the northern Adriatic Sea: Pore water and sediment studies

    SciTech Connect

    Hammond, D.E.; Berelson, W.M. ); Giordani, P.; Langone, L.; Frignani, M.; Ravaioli, M. )

    1990-01-09

    The northern Adriatic Sea has been plagued by problems of eutrophication. This area is relatively shallow (maximum depth = 60m), becoming stratified during the summer months which inhibits oxygen transport to bottom waters. Anthropogenic nutrient loading in rivers entering the northern Adriatic (Po River being the largest) has increased nutrient input to this system and stimulated algal growth. Cores were collected for studies of pore water and solid phase chemistry at 6 stations in this region. [sup 210]Pb was used to constrain sediment accumulation rates and a range of 0-0.5 cm/yr was determined at different stations. Excess [sup 234]Th was only found in the upper 1-2 cm, suggesting that bioturbation is largely restricted to shallow depths. Pore water profiles show evidence of irrigation, and mean diffusive fluxes for oxygen, silica phosphate and ammonia are generally 20-90% of the fluxes obtained from benthic chamber measurements. This is consistent with previous work in this area in which studies of radon fluxes indicated that irrigation plays an important role in sediment-water exchange. Pore water profiles in the northern portion of the study area (near the Po River Delta) were markedly different than profiles in the south; sediments in the north are substantially more acidic and have high concentrations of dissolved iron and phosphate. From the alkalinity vs. TCO[sub 2] relationship in sediment pore waters it appears that differences in reactions involving the reduction of iron oxides and the exchange of magnesium for iron in clays are responsible for this regional difference in pore water properties. Sediments close to the Po apparently undergo more iron-magnesium exchange, while more distal sediments are limited in their ability to do so. Other pore water observations are limited in their ability to do so. Other pore water observations and trends regarding the shape of the silica profiles (which show shallow maxima) will be discussed.

  11. Technical Note: Medium-term morphodynamics in an unprotected sandy beach of the Adriatic Sea

    NASA Astrophysics Data System (ADS)

    Postacchini, M.; Soldini, L.; Lorenzoni, C.; Mancinelli, A.

    2015-08-01

    In the recent years attention has been paid to the beach protection by means of soft and hard defenses. Along the Italian coasts of the Adriatic Sea, sandy beaches are the most common landscapes and around 70 % of the Marche-Region coasts (central Adriatic), is protected by defense structures. The longest free-from-obstacle nearshore area in the Region includes the beach of Senigallia, characterized by a multiple barred beach, frequently monitored during the last decades. The bathymetries surveyed in 2006, 2010, 2011, 2012 and 2013 show a good adaptation of the beach to the Dean-type equilibrium profile, though a strong short-/medium-term variability of the wave climate has been observed during the monitored periods. This suggests a slight influence of wave forcing on the long-term profiles, which seems to only depend on the sediment size. Further, the medium-term dynamics of the submerged bars and their geometric features have been related to the wave climate collected by a wave buoy located 40 km off Senigallia during the analyzed temporal windows. An overall interpretation of the complete dynamics, i.e. hydrodynamics (buoy data), sediment characteristics (equilibrium-profile A parameter) and morphodynamics (bathymetric surveys), suggests that the wave climate is fundamental for the morphodynamic changes of the beach in the medium term: waves coming from NNE/ESE are characterized by a larger/smaller steepness and induce seaward/shoreward bar migration, as well as bar smoothing/steepening. Moving southward, the bar dimension increases, while the equilibrium profile suggests a decrease of the sediment size in the submerged beach, this probably due to the presence of both harbor jetty and river mouth North of the investigated area.

  12. Testing the ability of barotropic models to simulate sea level extremes of meteorological origin in the Mediterranean Sea

    NASA Astrophysics Data System (ADS)

    Calafat, Francisco M.; Avgoustoglou, Euripides; Jordà, Gabriel; Flocas, Helena; Tsimplis, Mikis N.

    2014-05-01

    Storm surges are responsible for considerable damage to coastal property and loss of life every year. Furthermore, the damage from its combined effect with gradual sea level rise constitutes one of the most visible and costly effects of climate change. Understanding the mechanisms of storm surges as well as improving the predictive skill of storm surge models are hence of primary importance. This study investigates the ability of a 2D hydrodynamic model to simulate sea level extremes of meteorological origin in the Mediterranean Sea. For this purpose, the output of the model is compared to hourly sea level observations from a series of coastal tide gauge records covering most regions of the Mediterranean. It is found that the model underestimates the size of the sea level extremes at most stations. In terms of percentage, the underestimation is independent of the value of the extreme and, at some stations like Marseille, can be as large as 65%. Interestingly, in the Adriatic Sea, and more in particular at Trieste, the model can in some cases overestimate the magnitude of the extremes or even generate significant extreme events when they are in fact not present in the tide gauge record. The extent to which higher resolution sea level pressure (SLP) and wind forcing improve the sea level predictions is explored by comparing various simulations with atmospheric forcing of different resolution. Finally, the effect of the rapid deepening during explosive cyclone events on the performance of the ocean model as well as possible departures from the local inverse barometer effect during such events is also investigated. For the study of the events associated with explosive cyclones we use SLP and wind data with a horizontal resolution of about 7 km as simulated by the COSMO.GR model for 23 cases of explosive cyclogenesis spanning the period 2002-2010.

  13. Tectonic control on past circulation of the Mediterranean Sea: A model study of the Late Miocene

    NASA Astrophysics Data System (ADS)

    Meijer, P. Th.; Slingerland, R.; Wortel, M. J. R.

    2004-03-01

    We examine the effect of Late Miocene paleogeography on the circulation and water properties of the Mediterranean Sea by using an ocean circulation model. Results obtained for the past are compared to a control experiment with the present-day geometry. To focus on paleogeography, atmospheric forcing is always based on the present-day climatology. We seek insight that allows us to test ideas based on observations and to formulate new working hypotheses. The Late Miocene is examined first, since it represents an important stage in the evolution of the Mediterranean. The present-day model reproduces the main aspects of the surface to intermediate depth circulation and water properties. The model does not capture the deep circulation known to occur at present in both subbasins. When the subbasins are reconstructed to their Late Miocene shape (keeping intervening sills at present-day levels) the overall nature of the surface/intermediate depth circulation proves unaffected. The model, however, predicts intense deep circulation in the eastern Mediterranean, most likely due to the greater surface area of the reconstructed Adriatic Sea. Using the first paleoexperiment as a starting point several additional paleogeographical aspects are examined.

  14. Vertical distribution of the prokaryotic cell size in the Mediterranean Sea

    NASA Astrophysics Data System (ADS)

    La Ferla, R.; Maimone, G.; Azzaro, M.; Conversano, F.; Brunet, C.; Cabral, A. S.; Paranhos, R.

    2012-12-01

    Distributions of prokaryotic cell size and morphology were studied in different areas of the Mediterranean Sea by using image analysis on samples collected from surface down to bathypelagic layers (max depth 4,900 m) in the Southern Tyrrhenian, Southern Adriatic and Eastern Mediterranean Seas. Distribution of cell size of prokaryotes in marine ecosystem is very often not considered, which makes our study first in the context of prokaryotic ecology. In the deep Mediterranean layers, an usually-not-considered form of carbon sequestration through prokaryotic cells has been highlighted, which is consistent with an increase in cell size with the depth of the water column. A wide range in prokaryotic cell volumes was observed (between 0.045 and 0.566 μm3). Increase in cell size with depth was opposed to cell abundance distribution. Our results from microscopic observations were confirmed by the increasing HNA/LNA ratio (HNA, cells with high nucleic acid content; LNA, cells with low nucleic acid content) along the water column. Implications of our results on the increasing cell size with depth are in the fact that the quantitative estimation of prokaryotic biomass changes along the water column and the amount of carbon sequestered in the deep biota is enhanced.

  15. Probabilistic estimation of earthquake-induced tsunami occurrences in the Adriatic and northern Ionian seas

    NASA Astrophysics Data System (ADS)

    Armigliato, Alberto; Tinti, Stefano

    2010-05-01

    In the framework of the EU-funded project TRANSFER (Tsunami Risk ANd Strategies For the European Region we faced the problem of assessing quantitatively the tsunami hazard in the Adriatic and north Ionian Seas. Tsunami catalogues indicate that the Ionian Sea coasts has been hit by several large historical tsunamis, some of which of local nature (especially along eastern Sicily, eastern Calabria and the Greek Ionian Islands), while others had trans-basin relevance, like those generated in correspondence with the western Hellenic Trench. In the Adriatic Sea the historical tsunami activity is indeed lower, but not negligible: the most exposed regions on the western side of the basin are Romagna-Marche, Gargano and southern Apulia, while in the eastern side the Dalmatian and Albanian coastlines show the largest tsunami exposure. To quantitatively assess the exposure of the selected coastlines to tsunamis we used a hybrid statistical-deterministic approach, already applied in the recent past to the southern Tyrrhenian and Ionian coasts of Italy. The general idea is to base the tsunami hazard analyses on the computation of the probability of occurrence of tsunamigenic earthquakes, which is appropriate in basins where the number of known historical tsunamis is too scarce to be used in reliable statistical analyses, and the largest part of the tsunamis had tectonic origin. The approach is based on the combination of two steps of different nature. The first step consists in the creation of a single homogeneous earthquake catalogue starting from suitably selected catalogues pertaining to each of the main regions facing the Adriatic and north Ionian basins (Italy, Croatia, Montenegro, Greece). The final catalogue contains 6619 earthquakes with moment magnitude ranging from 4.5 to 8.3 and focal depth lower than 50 km. The limitations in magnitude and depth are based on the assumption that earthquakes of magnitude lower than 4.5 and depth greater than 50 km have no significant

  16. Population genetic structure and connectivity of the harmful dinoflagellate Alexandrium minutum in the Mediterranean Sea

    PubMed Central

    Casabianca, Silvia; Penna, Antonella; Pecchioli, Elena; Jordi, Antoni; Basterretxea, Gotzon; Vernesi, Cristiano

    2012-01-01

    The toxin-producing microbial species Alexandrium minutum has a wide distribution in the Mediterranean Sea and causes high biomass blooms with consequences on the environment, human health and coastal-related economic activities. Comprehension of algal genetic differences and associated connectivity is fundamental to understand the geographical scale of adaptation and dispersal pathways of harmful microalgal species. In the present study, we combine A. minutum population genetic analyses based on microsatellites with indirect connectivity (Ci) estimations derived from a general circulation model of the Mediterranean sea. Our results show that four major clusters of genetically homogeneous groups can be identified, loosely corresponding to four regional seas: Adriatic, Ionian, Tyrrhenian and Catalan. Each of the four clusters included a small fraction of mixed and allochthonous genotypes from other Mediterranean areas, but the assignment to one of the four clusters was sufficiently robust as proved by the high ancestry coefficient values displayed by most of the individuals (>84%). The population structure of A. minutum on this scale can be explained by microalgal dispersion following the main regional circulation patterns over successive generations. We hypothesize that limited connectivity among the A. minutum populations results in low gene flow but not in the erosion of variability within the population, as indicated by the high gene diversity values. This study represents a first and new integrated approach, combining both genetic and numerical methods, to characterize and interpret the population structure of a toxic microalgal species. This approach of characterizing genetic population structure and connectivity at a regional scale holds promise for the control and management of the harmful algal bloom events in the Mediterranean Sea. PMID:21593032

  17. A new morpho-bathymetric map of the Eastern Mediterranean Sea

    NASA Astrophysics Data System (ADS)

    Mascle, Jean; Brosolo, Laetitia

    2016-04-01

    A new morpho-bathymetric synthesis of the Eastern Mediterranean Sea has been compiled using a digital terrain model (DTM) based on a 100-meter grid. This DTM has been constructed using data provided by several peri-mediterranean Institutes, and collected using various swath bathymetry systems operated by different research vessels. One may estimate that 90% of the seabed extending by water depths higher than 2000m have been mapped using swath systems. The aim of this synthesis is chiefly to illustrate, in detail, the morphological features resulting from the various (sedimentary, tectonic, geochemical, magmatic, etc.) active geological processes operating on the four main physiographic domains, which characterize the Eastern Mediterranean Sea: the Calabria outer arc (Ionian Sea), the Mediterranean Ridge (most of the central basin), the Nile sedimentary cone (off Egypt) and the Eratosthenes seamount (south of Cyprus). For areas not yet covered by swath bathymetric systems the map has been completed by digital data extracted either from GEBCO or from EMODNET DTM files (http://www.gebco.net/data_and_products/gebco_digital_atlas/) (http://www.emodnet-hydrography.eu/). Several artifacts introduced by the use of these files, for example theoccurrences of their grids, can be detected along most of the steep continental slopes not yet mapped in detail, as well as in the southern domain of the Adriatic Sea. Similarly it has not been possible to systematically correct a few, but non-linear, discrepancies in Z values between various DTM files. Such discrepancies result either from the use of data collected by swath systems operating at different frequencies and/or from minor differences in seawater sound velocity corrections.

  18. Population genetic structure and connectivity of the harmful dinoflagellate Alexandrium minutum in the Mediterranean Sea.

    PubMed

    Casabianca, Silvia; Penna, Antonella; Pecchioli, Elena; Jordi, Antoni; Basterretxea, Gotzon; Vernesi, Cristiano

    2012-01-01

    The toxin-producing microbial species Alexandrium minutum has a wide distribution in the Mediterranean Sea and causes high biomass blooms with consequences on the environment, human health and coastal-related economic activities. Comprehension of algal genetic differences and associated connectivity is fundamental to understand the geographical scale of adaptation and dispersal pathways of harmful microalgal species. In the present study, we combine A. minutum population genetic analyses based on microsatellites with indirect connectivity (C(i)) estimations derived from a general circulation model of the Mediterranean sea. Our results show that four major clusters of genetically homogeneous groups can be identified, loosely corresponding to four regional seas: Adriatic, Ionian, Tyrrhenian and Catalan. Each of the four clusters included a small fraction of mixed and allochthonous genotypes from other Mediterranean areas, but the assignment to one of the four clusters was sufficiently robust as proved by the high ancestry coefficient values displayed by most of the individuals (>84%). The population structure of A. minutum on this scale can be explained by microalgal dispersion following the main regional circulation patterns over successive generations. We hypothesize that limited connectivity among the A. minutum populations results in low gene flow but not in the erosion of variability within the population, as indicated by the high gene diversity values. This study represents a first and new integrated approach, combining both genetic and numerical methods, to characterize and interpret the population structure of a toxic microalgal species. This approach of characterizing genetic population structure and connectivity at a regional scale holds promise for the control and management of the harmful algal bloom events in the Mediterranean Sea. PMID:21593032

  19. Classification of Satellite Derived Chlorophyll a Space-Time Series by Means of Quantile Regression: An Application to the Adriatic Sea

    NASA Astrophysics Data System (ADS)

    Girardi, P.; Pastres, R.; Gaetan, C.; Mangin, A.; Taji, M. A.

    2015-12-01

    In this paper, we present the results of a classification of Adriatic waters, based on spatial time series of remotely sensed Chlorophyll type-a. The study was carried out using a clustering procedure combining quantile smoothing and an agglomerative clustering algorithms. The smoothing function includes a seasonal term, thus allowing one to classify areas according to “similar” seasonal evolution, as well as according to “similar” trends. This methodology, which is here applied for the first time to Ocean Colour data, is more robust with respect to other classical methods, as it does not require any assumption on the probability distribution of the data. This approach was applied to the classification of an eleven year long time series, from January 2002 to December 2012, of monthly values of Chlorophyll type-a concentrations covering the whole Adriatic Sea. The data set was made available by ACRI (http://hermes.acri.fr) in the framework of the Glob-Colour Project (http://www.globcolour.info). Data were obtained by calibrating Ocean Colour data provided by different satellite missions, such as MERIS, SeaWiFS and MODIS. The results clearly show the presence of North-South and West-East gradient in the level of Chlorophyll, which is consistent with literature findings. This analysis could provide a sound basis for the identification of “water bodies” and of Chlorophyll type-a thresholds which define their Good Ecological Status, in terms of trophic level, as required by the implementation of the Marine Strategy Framework Directive. The forthcoming availability of Sentinel-3 OLCI data, in continuity of the previous missions, and with perspective of more than a 15-year monitoring system, offers a real opportunity of expansion of our study as a strong support to the implementation of both the EU Marine Strategy Framework Directive and the UNEP-MAP Ecosystem Approach in the Mediterranean.

  20. Coastal erosion impacts under climate change scenarios at the regional scale in the North Adriatic Sea

    NASA Astrophysics Data System (ADS)

    Critto, A.; Gallina, V.; Torresan, S.; Rizzi, J.; Zabeo, A.; Carniel, S.; Sclavo, M.; Marcomini, A.

    2012-04-01

    Global climate change is likely to pose additional pressures on coastal ecosystems by accelerating sea level rise, storms, flooding and erosion. Specifically, coastal erosion is an issue of major concern for estuarine and deltaic coastal areas and ecosystems and it is expected to increase in size and magnitude due to climate change forcing. Accordingly, the use of climate change scenarios in the assessment of coastal erosion risks could improve the development of sustainable adaptation strategies. In order to analyze the potential consequences of climate change on coastal erosion processes and evaluate the related impacts on coastal receptors (i.e. beaches, river mouths, wetlands and protected areas), a Regional Risk Assessment (RRA) methodology was developed and applied to the North Adriatic coast (Italy). Climate induced hazards were analyzed by means of regional hydrodynamic models that provide information about the main coastal erosion stressors (i.e. increases in mean sea-level, changes in wave height and variations in the extent of sediments deposition at the sea bottom) under climate change scenarios (i.e. regional climate projections). Site-specific environmental and socio-economic indicators (e.g. vegetation cover, geomorphology, sediment budget, protection level, population density and wetland extension) and hazard metrics were aggregated in the RRA methodology in order to develop exposure, susceptibility, risk and damage maps that identify and prioritize hot-spot areas and vulnerable targets at the regional scale. Future seasonal exposure maps of coastal erosion at the regional scale depict a worse situation in winter and autumn for the future period 2070-2100 and highlight hot-spot exposure areas surrounding the Po River Delta. Moreover, risk maps highlighted that the receptors (i.e. exposure units) at higher risk to coastal erosion are beaches, wetlands and river mouths with relevant percentages of the territory characterized by higher risk scores

  1. Space and time variability of the surface color field in the northern Adriatic Sea

    NASA Technical Reports Server (NTRS)

    Barale, Vittorio; Mcclain, Charles R.; Malanotte-Rizzoli, Paola

    1986-01-01

    A time series of coastal zone color scanner images for the years 1979 and 1980 was used to observe the spatial and temporal variability of bio-optical processes and circulation patterns of the northern Adriatic Sea on monthly, seasonal, and interannual scales. The chlorophyll-like pigment concentrations derived from satellite data exhibited a high correlation with sea truth measurements performed during seven surveys in the summer of both years. Comparison of the mean pigment fields indicates a general increase in concentration values and larger scales of coastal features from 1979 to 1980. This variability may be linked to the different patterns of nutrient influx due to coastal runoff in the 2 years. The distribution of surface features is consistent with the general cyclonic circulation pattern. The pigment heterogeneity appears to be governed by fluctuations of freshwater discharge, while the dominant wind fields do not appear to have important direct effects. The Po River presents a plume spreading predominantly in a southeastern direction, with scales positively correlated with its outflow. The spatial scales of the western coastal layer, in contrast, are negatively correlated with this outflow and the plume scales. Both results are consistent with, and may be rationalized by, recent theoretical and experimental results involving a dynamical balance between nonlinear advection and bottom friction, with alternate predominance of one of the two effects.

  2. Tenacibaculum adriaticum sp. nov., from a bryozoan in the Adriatic Sea.

    PubMed

    Heindl, Herwig; Wiese, Jutta; Imhoff, Johannes F

    2008-03-01

    A rod-shaped, translucent yellow-pigmented, Gram-negative bacterium, strain B390(T), was isolated from the bryozoan Schizobrachiella sanguinea collected in the Adriatic Sea, near Rovinj, Croatia. 16S rRNA gene sequence analysis indicated affiliation to the genus Tenacibaculum, with sequence similarity levels of 94.8-97.3 % to type strains of species with validly published names. It grew at 5-34 degrees C, with optimal growth at 18-26 degrees C, and only in the presence of NaCl or sea salts. In contrast to other type strains of the genus, strain B390(T) was able to hydrolyse aesculin. The predominant menaquinone was MK-6 and major fatty acids were iso-C(15 : 0), iso-C(15 : 0) 3-OH and iso-C(15 : 1). The DNA G+C content was 31.6 mol%. DNA-DNA hybridization and comparative physiological tests were performed with type strains Tenacibaculum aestuarii JCM 13491(T) and Tenacibaculum lutimaris DSM 16505(T), since they exhibit 16S rRNA gene sequence similarities above 97 %. These data, as well as phylogenetic analyses, suggest that strain B390(T) (=DSM 18961(T) =JCM 14633(T)) should be classified as the type strain of a novel species within the genus Tenacibaculum, for which the name Tenacibaculum adriaticum sp. nov. is proposed. PMID:18319452

  3. Ventilation of the Mediterranean Sea constrained by multiple transient tracer measurements

    NASA Astrophysics Data System (ADS)

    Stöven, T.; Tanhua, T.

    2014-06-01

    Ventilation is the primary pathway for atmosphere-ocean boundary perturbations, such as temperature anomalies, to be relayed to the ocean interior. It is also a conduit for gas exchange between the interface of atmosphere and ocean. Thus it is a mechanism whereby, for instance, the ocean interior is oxygenated and enriched in anthropogenic carbon. The ventilation of the Mediterranean Sea is fast in comparison to the world ocean and has large temporal variability. Here we present transient tracer data from a field campaign in April 2011 that sampled a unique suite of transient tracers (SF6, CFC-12, 3H and 3He) in all major basins of the Mediterranean. We apply the transit time distribution (TTD) model to the data in order to constrain the mean age, the ratio of the advective / diffusive transport and the number of water masses significant for ventilation. We found that the eastern part of the eastern Mediterranean can be reasonably described with a one-dimensional inverse Gaussian TTD (IG-TTD), and thus constrained with two independent tracers. The ventilation of the Ionian Sea and the western Mediterranean can only be constrained by a linear combination of IG-TTDs. We approximate the ventilation with a one-dimensional, two inverse Gaussian TTD (2IG-TTD) for these areas and demonstrate a possibility of constraining a 2IG-TTD from the available transient tracer data. The deep water in the Ionian Sea has a mean age between 120 and 160 years and is therefore substantially older than the mean age of the Levantine Basin deep water (60-80 years). These results are in contrast to those expected by the higher transient tracer concentrations in the Ionian Sea deep water. This is partly due to deep water of Adriatic origin having more diffusive properties in transport and formation (i.e., a high ratio of diffusion over advection), compared to the deep water of Aegean Sea origin that still dominates the deep Levantine Basin deep water after the Eastern Mediterranean Transient

  4. Biochemical biomarker responses to pollution in selected sentinel organisms across the Eastern Mediterranean and the Black Sea.

    PubMed

    Catherine, Tsangaris; Vanessa, Moschino; Evangelia, Strogyloudi; Valentina, Coatu; Andreja, Ramšak; Rana, Abu Alhaija; Susana, Carvalho; Serena, Felline; Alisa, Kosyan; Yiota, Lazarou; Ioannis, Hatzianestis; Andra, Oros; Daniela, Tiganus

    2016-01-01

    Pollution effects were assessed by means of biochemical biomarkers (catalase, glutathione S-transferase and acetylcholinesterase activities, and metallothioneins content) in five species at selected coastal sites across the Eastern Mediterranean and the Black Sea. The mussel Mytilus galloprovincialis, a well-established sentinel species, was investigated in the Adriatic Sea, Aegean Sea, and Black Sea. The mussel Brachidontes pharaonis and the striped red mullet Mullus surmuletus were used in the Levantine Sea where M. galloprovincialis is not present. The white seabream Diplodus sargus sargus and the gastropod Rapana venosa were additionally sampled in the Adriatic and the Black Sea, respectively. Mussels showed catalase, glutathione S-transferase, and acetylcholinesterase responses to pollution in most geographical areas while the response of metallothioneins was restricted to a few sites. R. venosa showed marked responses of catalase and metallothioneins whereas both fish species did not generally exhibit variations in biomarker values among sites. The approach based on the reference deviation concept using the "Integrated Biological Responses version 2" index was useful for the interpretation of overall biomarker responses. PMID:26396017

  5. The rock magnetic characteristics of last glacial cycle loess from the island of Susak (Adriatic Sea, Croatia)

    NASA Astrophysics Data System (ADS)

    Hambach, Ulrich; Duchoslav, Maguerita; Rolf, Christian; Wacha, Lara; Frechen, Manfred; Galovic, Lidija

    2010-05-01

    Loess is by far the most important terrestrial archive that provides detailed palaeoclimatic information for the whole Quaternary. Loess covers wide areas in Asia and Southeast Europe where continental and sub-continental climates predominate. In Mediterranean climate settings, however, loess deposits are almost absent and the few existing sites provide invaluable palaeoclimatic information. Heller & Liu (1984) were the first who used magnetic susceptibility variations in Chinese loess to correlate the loess deposits to marine records. The susceptibility variations in the loess-palaeosol couplets resemble the pattern of the global ice volume record with higher values in palaeosols (interglacials) and lower values in loess (glacials). In most parts of the Eurasian loess belt, the intensity of pedogenesis leads to enhancement of magnetic minerals in soils. However, in other parts of the world under different climatic conditions, even depletion of the magnetic fraction could be observed. Furthermore, the wind strength during dust transport and loess deposition also seems to control the magnetic mineralogy. With stronger winds, minerals with higher density such as iron oxides are enriched during aeolian transport. Here we report on first results from a detailed rock magnetic investigation of a loess sequence from the Adriatic coast of Croatia. The Pjeskokop site is located on the island of Susak in the northern Dalmatian archipelago. On Susak, aeolian sands, sandy loess and loess have been deposited on Cretaceous marine limestones and form an up to 20 metres thick Pleistocene sediment blanket (Cremaschi 1990). At the Pjeskokop site, non-oriented samples were collected with narrow spacing (~2 cm) from a more than 11 metres high section. All samples were subjected to standard rock laboratory procedures. Detailed petrographical and grain size studies on parallel samples are in progress. A strongly rubified pedo-complex forms the base of the sequence. Weakly developed

  6. Historical ecology of the northern Adriatic Sea: Field methods and coring device

    NASA Astrophysics Data System (ADS)

    Haselmair, Alexandra; Gallmetzer, Ivo; Tomasovych, Adam; Stachowitsch, Michael; Zuschin, Martin

    2014-05-01

    For an ongoing study on the historical ecology of the northern Adriatic Sea, the objective was to retrieve a high number of sediment cores at seven sampling stations spread across the entire basin. One set of cores is intended for sediment analyses including radiometric Pb-sediment-dating, grain size, TOC, TAC and heavy metal analyses. The other set of cores delivered enough shelly remains of endo- or epibenthic hard part producers (e.g. molluscs, crustaceans, echinoderms) to enable the reconstruction of death assemblages in core layers from top to bottom. The down-core changes of such assemblages record ecological shifts in a marine environment that has endured strong human impacts over several centuries. A 1.5 m-long core could, according to the available sedimentation data for the area, cover up to 2000 or even more years of ecological history. The coring method had to meet the following requirements: a) deliver 1.5-m-long cores from different sediment settings (mud to sand, reflecting a wide range of benthic habitats in the northern Adriatic); b) enable quick and easy deployment to ensure that multiple cores can be taken at the individual sampling stations within a short time; c) be relatively affordable and allow handling by the researchers themselves, potentially using a small vessel in order to further contain the operating costs. Two types of UWITEC™ piston corers were used to meet these requirements. A model with 90 mm of diameter (samples for sediment analysis) and another one with 160 mm, specifically designed to obtain the large amount of material needed for shell analysis, successfully delivered a total of 54 cores. The device consists of a stabilizing tripod and the interchangeable coring cylinders. It is equipped with a so-called hammer action that makes it possible, at least for the smaller cylinder, to penetrate even harder sediments. A closing mechanism of the corer retains the sediment in the cylinder upon extraction; it works either

  7. Eastern Mediterranean high resolution paleoclimate investigations using south Adriatic finely laminated sediment: preliminary data

    NASA Astrophysics Data System (ADS)

    Goudeau, Marie-Louise; Robert, Brice; Jilbert, Tom; Fhlaithearta, Shauna Ni; Zonneveld, K. A. F.; Versteegh, G. J. M.; Grauel, A.; Bernasconi, S.; de Lange, G. J.

    2010-05-01

    The formation of distinct organic-rich units (sapropels) in the Medditerenean is well-known, and intensively studied , however less is known of the smaller scale variability during their formation. Multicore GeoB 107-39-03 was taken in 2006, in the central part of the straits of Otranto, south Adriatic. Over the main part of the core, fine, sub-milimetric scale laminae are found. Preliminary dating indicates a Sapropel 1 age for these sediments. The fine, laminae permit high-resolution climate variability to be studied in this area during sapropel formation. Besides conventional geochemical analyses on discrete samples (XRF, ICP-OES, organic C/N, 13C) a novel technique was used to investigate the sediment chemistry at the laminae scale: the sediment has been resin-impregnated to enable laser ablation coupled to ICP-MS analyses (LA-ICP-MS). This method recently developed (Jilbert et al., 2008) permits extremely high resolution geochemical profiling of the laminated sediment, to unravel the forcing mechanisms generating the laminae. Furthermore, in order to compare the data to modern sediment geochemistry, a series of analyses were carried out on a batch of sediment surface samples in collaboration with the MOCCHA project partners (see Posters/Talks in session OS15). This work is supported by the EUROCORES/EUROMARC Program of the European Science Foundation (NWO.817.01.002 MOCCHA project).

  8. Hydrography in the Mediterranean Sea during a cruise with RV Poseidon in April 2014

    NASA Astrophysics Data System (ADS)

    Hainbucher, D.; Cardin, V.; Siena, G.; Hübner, U.; Moritz, M.; Drübbisch, U.; Basan, F.

    2015-09-01

    We report on data from an oceanographic cruise in the Mediterranean Sea on the German research vessel Poseidon in April 2014. Data were taken on a west-east section, starting at the Strait of Gibraltar and ending south-east of Crete, as well on sections in the Ionian and Adriatic Sea. The objectives of the cruise were threefold: to contribute to the investigation of the spatial evolution of the Levantine Intermediate Water (LIW) properties and of the deep water masses in the eastern Mediterranean Sea, and to investigate the mesoscale variability of the upper water column. The measurements include salinity, temperature, oxygen and currents and were conducted with a conductivity, temperature and depth(CTD)/rosette system, an underway CTD and an acoustic Doppler current profiler (ADCP). The sections are on tracks which have been sampled during several other cruises, thus supporting the opportunity to investigate the long-term temporal development of the different variables. The use of an underway CTD made it possible to conduct measurements of temperature and salinity with a high horizontal spacing of 6 nm between stations and a vertical spacing of 1 dbar for the upper 800 m of the water column.

  9. Tectonic control on past circulation of the Mediterranean Sea; A model approach

    NASA Astrophysics Data System (ADS)

    Meijer, P.; Wortel, R.; Slingerland, R.

    2003-04-01

    The sediments of the Mediterranean basin tell us that the circulation and water properties of the sea have changed through time. While some of these changes appear closely related to variations in climate, other aspects have been tentatively linked to changes in the geometry of the sub-basins and of the intervening straits. These changes in geometry have been profound and result from tectonic activity associated with the last stages of convergence between the African plate and the Eurasian plate. We study the effects of paleogeography on Mediterranean circulation using an oceanic general circulation model. Our first focus is the Late Miocene (Tortonian) when sub-basin shape was significantly different from the present-day (wider Adriatic Sea, narrow Tyrrhenian Sea) and the Mediterranean as a whole was connected to the Atlantic ocean via two gateways: across southern Iberia and through northwestern Africa. In order to isolate the effects of paleogeography we subject both a model for the present-day and a first model for the Late Miocene to the present-day atmospheric forcing. Moreover, in the paleo-experiment, the depth of the straits connecting the western and eastern subbasins and that of the Mediterranean-Atlantic gateways is kept at 300 meter approximately the present-day depth of the straits of Gibraltar and Sicily. At surface and intermediate levels the circulation and water properties thus found with the Late Miocene geometry are similar to the present-day situation. Location and intensity of vertical mixing are different, however, which points to an effect of basin geometry on deep circulation. Subsequent experiments are aimed at determining the effect of specific aspects of the paleogeography: presence or absence of a connection with the Paratethys and the role of straits across the early Apennines, for example.

  10. Future sea-level rise in the Mediterranean Sea

    NASA Astrophysics Data System (ADS)

    Galassi, Gaia; Spada, Giorgio

    2014-05-01

    Secular sea level variations in the Mediterranean Sea are the result of a number of processes characterized by distinct time scales and spatial patterns. Here we predict the future sea level variations in the Mediterranean Sea to year 2050 combining the contributions from terrestrial ice melt (TIM), glacial isostatic adjustment (GIA), and the ocean response (OR) that includes the thermal expansion and the ocean circulation contributions. The three contributions are characterized by comparable magnitudes but distinctly different sea-level fingerprints across the Mediterranean basin. The TIM component of future sea-level rise is taken from Spada et al. (2013) and it is mainly driven by the melt of small glaciers and ice caps and by the dynamic ice loss from Antarctica. The sea-level fingerprint associated with GIA is studied using two distinct models available from the literature: ICE-5G(VM2) (Peltier, 2004) and the ice model progressively developed at the Research School of Earth Sciences (RSES) of the National Australian University (KL05) (see Fleming and Lambeck, 2004 and references therein). Both the GIA and the TIM sea-level predictions have been obtained with the aid of the SELEN program (Spada and Stocchi, 2007). The spatially-averaged OR component, which includes thermosteric and halosteric sea-level variations, recently obtained using a regional coupled ocean-atmosphere model (Carillo et al., 2012), vary between 2 and 7 cm according to scenarios adopted (EA1B and EA1B2, see Meehl at al., 2007). Since the sea-level variations associated with TIM mainly result from the gravitational interactions between the cryosphere components, the oceans and the solid Earth, and long-wavelength rotational variations, they are characterized by a very smooth global pattern and by a marked zonal symmetry reflecting the dipole geometry of the ice sources. Since the Mediterranean Sea is located in the intermediate far-field of major ice sources, TIM sea-level changes have sub

  11. Effects of the Eastern Mediterranean Sea circulation on the thermohaline properties as recorded by fixed deep-ocean observatories

    NASA Astrophysics Data System (ADS)

    Bensi, Manuel; Velaoras, Dimitris; Meccia, Virna L.; Cardin, Vanessa

    2016-06-01

    Temperature and salinity time-series from three fixed observatories in the Eastern Mediterranean Sea (EMed) are investigated using multi-annual (2006-2014), high-frequency (up to 3 h sampling rate) data. Two observatories are deployed in the two dense water formation (DWF) areas of the EMed (Southern Adriatic Sea, E2-M3A; Cretan Sea, E1-M3A) and the third one (Southeast Ionian Sea, PYLOS) lays directly on the intermediate water masses pathway that connects the DWF sources. The long-term variations of the hydrological characteristics at the observatories reflect the oscillating large-scale circulation modes of the basin (i.e. BiOS-Bimodal Oscillating System and internal thermohaline pump theories). In particular, between 2006 and 2014 an anti-correlated behaviour of the intermediate layer (200-600 m) salinity between the Adriatic and Cretan Sea observatories is verified. This behaviour is directly linked to reversals of the North Ionian Gyre, which appeared cyclonic during 2006-2011 and turned anticyclonic after 2011. Statistical analysis suggests that the travel time of the intermediate salinity maximum signal between the Cretan and Adriatic Sea is roughly 1.5 years, in good agreement with the analysis of additionally presented ARGO data as well as previous literature references. We argue that the understanding of such oscillations provides important foresight on future DWF events, as increased salinity may act as a crucial preconditioning factor for DWF processes. Additionally, energy spectrum analysis of the time-series revealed interesting short-term variability connected to mesoscale activity at the observatories. Hence, the sustain of permanent observatories able to monitor oceanic parameters at high sampling rates may play a key role in understanding both climatic and oceanic processes and trends.

  12. Modeling the barotropic response of the Mediterranean sea level to atmospheric pressure forcing

    NASA Astrophysics Data System (ADS)

    Natsiopoulos, Dimitrios A.; Vergos, Georgios S.; Tziavos, Ilias N.

    2014-05-01

    An important characteristic of the Earth's atmosphere with direct impact on the marine environmental and Earth's gravity field are the variations of atmospheric pressure as it often determines wind and weather patterns across the globe. Variations in atmospheric pressure and especially low atmospheric systems affect the values of radar altimeter sea level anomalies (SLA). This response of sea level is closed to the Inverse Barometer (IB) correction given by the altimeters within their geophysical data records. In this work, altimetric data sets from the satellite remote sensing mission of Jason-2, along with their total IB corrections acquired by the on-board altimeters, have been used for a period of forty days between October and November 2013. This period was characterized by extreme low-pressure fields over the Mediterranean Sea and especially in the area of the Ionian and Adriatic Seas and over the island of Rhodes, Greece. The Jason-2 along-track records of the SLA have been used to study both the sea level response to atmospheric pressure change over short time scales (such as ten days) and examine if the barometer correction (local and global) given by the altimeter is close to the expected response (-1 cm/mbar) of sea level to atmospheric pressure change. For the latter, atmospheric pressure data for the period under study were available from the Live Access Server (LAS) of NOAA, as well, provided at four times per day intervals in a grid format. From the LAS atmospheric pressure data, the IB effect was computed and compared with the one provided by the altimeter for its external evaluation. Finally, a regional multiple regression analysis between sea level anomalies, the LAS atmospheric pressure and wind speed components is carried out to model the barotropic response of the Mediterranean to atmospheric wind and pressure forcing.

  13. Seasonal statistics of highest sea levels along the northwestern Adriatic coast

    NASA Astrophysics Data System (ADS)

    Lamberti, A.; Masina, M.

    2012-04-01

    Joint spatial analyses of marine flood drivers may provide important insights into the assessment of the related impacts on the low-lying coastal areas of the northwestern Adriatic coast. Identification of seasonality in the highest sea levels represents a first step in performing the analysis. Seasonal variability is investigated in the long term tidal gauge series of Punta della Salute (Venezia), Molo Sartorio (Trieste) and Porto Corsini (Ravenna) and in the short and fragmentary one of Rimini for which the available historical information, extracted from Hydrological Annals and provided by ISPRA and the Institute of Marine Science - CNR of Trieste , includes data collected with different criteria (monthly high water levels, daily high and low tides, hourly values and ten-minutes records). Following Carter and Challenor (1981) the variability of extreme high sea levels is initially studied modelling monthly maxima separately with the Generalized Extreme Value (GEV) distribution, combining them to extrapolate the distribution of annual maxima and comparing the resulting curve with that derived from the canonical approach based on annual maxima series. Monthly and annual maxima have been first declustered selecting the maximum value in a 78 hrs window and, aiming to remove the effect of sea level rise and local subsidence, detrended subtracting the regularized mean sea level. After the removal of these effects, monthly and annual maxima do not exhibit a specific multi-decadal trend. The results, expressed in terms of monthly average values, show instead a uniform behaviour for the analyzed stations, characterized by a large variability of extreme sea levels throughout a year with a systematic concentration of potential dangerous events in late autumn and winter seasons. In spite of the limited extension of the Adriatic basin, the most significant historical storms responsible of disastrous impacts on coastal areas were recorded in different years from the two

  14. Levels of total mercury in marine organisms from Adriatic Sea, Italy.

    PubMed

    Perugini, Monia; Visciano, Pierina; Manera, Maurizio; Zaccaroni, Annalisa; Olivieri, Vincenzo; Amorena, Michele

    2009-08-01

    The presence of total mercury in fish, crustacean and cephalopod from Adriatic Sea, was investigated. The highest concentrations were observed in decreasing order in: Norway lobster (0.97 +/- 0.24 mg/kg; mean +/- SE), European hake (0.59 +/- 0.14 mg/kg), red mullet (0.48 +/- 0.09 mg/kg), blue whiting (0.38 +/- 0.09 mg/kg), Atlantic mackerel (0.36 +/- 0.08 mg/kg) and European flying squid (0.25 +/- 0.03 mg/kg). A significant difference (p < 0.01) was found between the levels of total mercury in Norway lobster and those detected in all other species. The 25% of all samples exceeded the maximum limit fixed by Commission Regulation (EC) No 1881/2006. The results show that fish and fishery products can exceed the maximum levels and stress the need of more information for consumers in particular for people that eat large amount of fish. PMID:19434348

  15. Meteoceanographic premises for structural design purposes in the Adriatic Sea: Acquisition and processing of data

    SciTech Connect

    Rampolli, M.; Biancardi, A.; Filippi, G. De

    1996-12-31

    In 1993 the leading international standards (ISO, APOI RP2A) for the design of offshore structures drastically changed the procedure for the definition of hydrodynamic forces. In particular oil companies are required to have a detailed knowledge of the weather of the areas where they operate, if they want to maintain the previous results. Alternatively, more conservative hydrodynamic forces must be considered in the design phase. Such an increase, valuable in 20--30% of total hydrodynamic force, means heavier platform structures in new projects, and more critical elements to be inspected in existing platforms. In 1992, in order to have more reliable and safe transports to and from the platforms, Agip installed a meteo-marine sensor network in Adriatic Sea, on 13 of the over 80 producing platforms. Data collected are sent to shore via radio and operators can use real time data or 12-hour wave forecast, obtained by a statistic forecasting model. Taking advantage by such existing instruments, a project was undertaken in 1993 with the purpose of determining the extreme environmental parameters to be used by structural engineers. The network has been upgraded in order to achieve directional information of the waves and to permit short term analysis. This paper describes the data acquisition system, data processing and the achieved results.

  16. Ecosystem exploitation and trophodynamic indicators: A comparison between the Northern Adriatic Sea and Southern New England

    NASA Astrophysics Data System (ADS)

    Pranovi, Fabio; Link, Jason S.

    2009-04-01

    In an ecosystem-based resource management context, it is crucial to assess the relationships between community structure and ecosystem function and how those relationships change with resource extraction. To elucidate how changes in resource use can affect community structure and ecosystem function, we executed a comparative analysis of two different ecosystems subjected to notable fishing pressure. We contrasted the Northern Adriatic Sea (NAS) and Southern New England (SNE) ecosystems by examining outputs from comparable steady-state models. Both ecosystems have relatively high fishing pressure and a high biomass of benthic invertebrates. The basic structure of the food webs shows differences both in the number and definition of the functional groups, as described in the models. Fisheries, on the contrary, show similarities both in terms of catches and discards. Almost all statistics summarizing the structure and flows showed values three times higher in the SNE than in the NAS ecosystem, but despite this difference the two ecosystems exhibited similar, overall properties. Biomass ratios and the Mixed Trophic Impact (MTI) analysis showed that both ecosystems are dominated by the benthic compartment. Removing the biomass effect, however, shows a clear top-down effect, with a high rank achieved by fishing activities. In general terms, the low mean trophic level of catches and the high primary production required (PPR) values result in a high overexploitation level of the ecosystem, as highlighted by the L index. We conclude by exploring how comparative studies will continue to be valuable as ecosystem-based management is further implemented.

  17. {sup 210}Pb dating of sediments from the central and northern Adriatic Sea: deposition and preservation of sedimentary organic carbon

    SciTech Connect

    Hamilton, T. F., LLNL

    1998-04-01

    Lead-210 ({sup 21O}Pb) and organic C depth distribution profiles in sediments from the northern and central Adriatic Sea were measured as part of the EEC funded project on Eutrophic Limits of the Northern Adriatic (ELNA). {sup 210}Pb derived mass-accumulation rates decrease southward from between 0.15 and 0.2 g cm{sup -2}y{sup -1} close to the Po River outflow (> 24 m, water depth) to less than 0.04 g cm{sup -2}y{sup -1} in the Jabuka Pit (246 m, water depth) in the central Adriatic Sea. The mass- accumulation rates obtained in the Jabuka Pit correspond to mean sedimentation rates of about 0.03 cm y{sup -1} (ref. porosity = 0.5) and fall between 5 to 20 times lower than rates found for north Adriatic shelf cores. Estimated sedimentation rates are considered as upper limits because of the possible effects of bioturbation and physical disturbance on the {sup 21O}Pb sedimentary record but are consistent with data from previous work. Rates of sediment accumulation and carbon burial appear to be strongly influenced by the transport of fluvial materials from land and transport of fine-grained particles. First-order estimates of organic C burial rates into surface sediment ranged from 1 to 0.028 mMol cm{sup -2}y{sup -1} between the Po delta and the Jabuka Pit regions, respectively. We estimate that a maximum of 50% of organic C preserved in surface sediment may be derived from biological production in the overlying water column.

  18. Climatological variations of total alkalinity and total dissolved inorganic carbon in the Mediterranean Sea surface waters

    NASA Astrophysics Data System (ADS)

    Gemayel, E.; Hassoun, A. E. R.; Benallal, M. A.; Goyet, C.; Rivaro, P.; Abboud-Abi Saab, M.; Krasakopoulou, E.; Touratier, F.; Ziveri, P.

    2015-12-01

    A compilation of data from several cruises between 1998 and 2013 was used to derive polynomial fits that estimate total alkalinity (AT) and total dissolved inorganic carbon (CT) from measurements of salinity and temperature in the Mediterranean Sea surface waters. The optimal equations were chosen based on the 10-fold cross-validation results and revealed that second- and third-order polynomials fit the AT and CT data respectively. The AT surface fit yielded a root mean square error (RMSE) of ± 10.6 μmol kg-1, and salinity and temperature contribute to 96 % of the variability. Furthermore, we present the first annual mean CT parameterization for the Mediterranean Sea surface waters with a RMSE of ± 14.3 μmol kg-1. Excluding the marginal seas of the Adriatic and the Aegean, these equations can be used to estimate AT and CT in case of the lack of measurements. The identified empirical equations were applied on the 0.25° climatologies of temperature and salinity, available from the World Ocean Atlas 2013. The 7-year averages (2005-2012) showed that AT and CT have similar patterns with an increasing eastward gradient. The variability is influenced by the inflow of cold Atlantic waters through the Strait of Gibraltar and by the oligotrophic and thermohaline gradient that characterize the Mediterranean Sea. The summer-winter seasonality was also mapped and showed different patterns for AT and CT. During the winter, the AT and CT concentrations were higher in the western than in the eastern basin. The opposite was observed in the summer where the eastern basin was marked by higher AT and CT concentrations than in winter. The strong evaporation that takes place in this season along with the ultra-oligotrophy of the eastern basin determines the increase of both AT and CT concentrations.

  19. Climatological variations of total alkalinity and total inorganic carbon in the Mediterranean Sea surface waters

    NASA Astrophysics Data System (ADS)

    Gemayel, E.; Hassoun, A. E. R.; Benallal, M. A.; Goyet, C.; Rivaro, P.; Abboud-Abi Saab, M.; Krasakopoulou, E.; Touratier, F.; Ziveri, P.

    2015-08-01

    A compilation of several cruises data from 1998 to 2013 was used to derive polynomial fits that estimate total alkalinity (AT) and total inorganic carbon (CT) from measurements of salinity and temperature in the Mediterranean Sea surface waters. The optimal equations were chosen based on the 10-fold cross validation results and revealed that a second and third order polynomials fit the AT and CT data respectively. The AT surface fit showed an improved root mean square error (RMSE) of ±10.6 μmol kg-1. Furthermore we present the first annual mean CT parameterization for the Mediterranean Sea surface waters with a RMSE of ±14.3 μmol kg-1. Excluding the marginal seas of the Adriatic and the Aegean, these equations can be used to estimate AT and CT in case of the lack of measurements. The seven years averages (2005-2012) mapped using the quarter degree climatologies of the World Ocean Atlas 2013 showed that in surface waters AT and CT have similar patterns with an increasing eastward gradient. The surface variability is influenced by the inflow of cold Atlantic waters through the Strait of Gibraltar and by the oligotrophic and thermohaline gradient that characterize the Mediterranean Sea. The summer-winter seasonality was also mapped and showed different patterns for AT and CT. During the winter, the AT and CT concentrations were higher in the western than in the eastern basin, primarily due to the deepening of the mixed layer and upwelling of dense waters. The opposite was observed in the summer where the eastern basin was marked by higher AT and CT concentrations than in winter. The strong evaporation that takes place in this season along with the ultra-oligotrophy of the eastern basin determines the increase of both AT and CT concentrations.

  20. High-resolution simulations of heavy precipitation events: role of the Adriatic SST and air-sea interactions

    NASA Astrophysics Data System (ADS)

    Davolio, Silvio; Stocchi, Paolo

    2016-04-01

    Strong Bora and Sirocco winds over the Adriatic Sea favour intense air-sea interactions and are often associated with heavy rainfall that affects the mountainous areas surrounding the basin. A convection-permitting model (MOLOCH) has been implemented at high resolution (2 km) in order to analyse several precipitation events over northern Italy, occurred during different seasons of the year and presenting different rainfall characteristics (stratiform, convective, orographic), and to possibly identify the relevant physical mechanisms involved. With the aim of assessing the impact of the sea surface temperature (SST) and surface fluxes on the intensity and location of the rainfall, sensitivity experiments have been performed taking into account the possible variability of SST analysis for model initialization. The model has been validated and specific diagnostic tools have been developed and applied to evaluate the vertically integrated moisture fluxes feeding the precipitating system or to compute a water balance in the atmosphere over the sea. The results show that the Adriatic Sea plays a role in determining the boundary layer characteristics through exchange of heat and moisture thus modifying the low-level flow dynamics and its interaction with the orography. This in turn impacts on the rainfall. Although the results vary among the analysed events, the precise definition of the SST and its evolution can be relevant for accurate precipitation forecasting.

  1. Foraminiferal assemblages and trophic state in coastal sediments of the Adriatic Sea

    NASA Astrophysics Data System (ADS)

    Sabbatini, Anna; Bonatto, Sonia; Bianchelli, Silvia; Pusceddu, Antonio; Danovaro, Roberto; Negri, Alessandra

    2012-12-01

    The environmental variables that influence the abundance and biodiversity of foraminifera in shallow-water settings are poorly understood. In order to help address this problem, we investigated abundance, biomass and biodiversity of living (as Rose-Bengal stained) benthic foraminifera together with the quantity and biochemical composition (in terms of phytopigment, protein, lipid, carbohydrate and biopolymeric carbon) of the organic matter in coastal sediments of the Central Adriatic Sea. Sediment samples were collected in the Portonovo Bay in May, July and October 2008 and February 2009, and the organic matter quantity and biochemical composition and benthic foraminiferal abundance and assemblage composition were analysed in the top 1 cm. Uni- and multi-variate analyses of variance revealed clear temporal variability of all the investigated variables as well as relationships between the composition of the foraminiferal assemblages and the quantity and quality of the food sources. The foraminiferal abundance and species composition changed significantly between the four sampling periods, reflecting the temporal (seasonal) variability in the quantity and nutritional quality of the food sources. Lipids, among all other organic compounds, explain significant portions of the variance of both foraminiferal abundance and biomass. In winter, a strong phytoplankton bloom led to an increased quantity of nutritionally available organic matter on the sea floor, which in turn was associated with a bloom of Leptohalysis scottii and Psammophaga sp. 1. These two foraminiferal species thus displayed an opportunistic behaviour in response to the pulse of organic carbon of high nutritional quality. We suggest that these species can be used as indicators of benthic eutrophication in shallow waters.

  2. Eutrophication and environmental policy in the Mediterranean Sea: a review.

    PubMed

    Karydis, Michael; Kitsiou, Dimitra

    2012-08-01

    The Mediterranean Sea is a semienclosed basin connected with the open sea mainly through the Strait of Gibraltar. Due to the circulation pattern and the long residence time ranging between 80 and 100 years, the Mediterranean Sea is a sensitive environment to eutrophication pressures. The main body of water of the Mediterranean is characterized by very low nutrient concentrations, and therefore, the Mediterranean is classified among the most oligotrophic (very poor waters in nutrients) seas of the world's oceans. However, some coastal areas, mainly in the northern part of the basin, receive excessive loads of nutrients from sewage effluents, river fluxes, aquaculture farms, fertilizers, and industrial facilities, showing intense eutrophic phenomena with many adverse effects for the marine ecosystem and humans. Various national and international authorities, in addition to monitoring, have taken legal and administrative measures to mitigate eutrophication trends in the area. The Mediterranean environment is a good paradigm of integration of extensive legal framework, scientific knowledge, and administrative practices. The Barcelona Convention, the Mediterranean Action Plan, and European Union Directives on water quality and coastal management, together with scientific information derived from international research programs in the Mediterranean, provide a sound background for practical actions in eutrophication problems. In the present work, the problem of coastal eutrophication in the Mediterranean is reviewed in connection with public policies of the Mediterranean States based on national and international legislation and scientific knowledge on Mediterranean oceanography-ecology and actions coordinated by international bodies. These common actions and practices on coastal management are also discussed in relation to the need for sustainable development and protection of the coastal zone in the Mediterranean Sea. PMID:21956336

  3. An observatory system for physical and biogeochemical parameters in the northern Adriatic Sea: the "Acqua Alta" oceanographic platform

    NASA Astrophysics Data System (ADS)

    Benetazzo, Alvise; Barbariol, Francesco; Bastianini, Mauro; Bergamasco, Andrea; Bergamasco, Filippo; Bernardi Aubry, Fabrizio; Bertotti, Luciana; Bonaldo, Davide; Cavaleri, Luigi; Carniel, Sandro; Falcieri, Francesco M.; Finotto, Stefania; Lester, Graham; Licer, Matjaz; Malacic, Vlado; Minuzzo, Tiziano; Sclavo, Mauro

    2015-04-01

    during winter 2012. Biological (phyto- and zooplankton) and chemical (dissolved nutrients) measurements are routinely acquired at "Acqua Alta", with periodic sampling on the water column within the Italian Long Term Ecological Research (LTER) network. Two high-resolution webcams have been installed on the submerged structures at -3m and -15m. The main aim is the evaluation of ichthyologic populations of the area for long-term ecological studies, and the real-time images represent a valuable tool as early-warning systems (large mucus aggregates, jellyfish swarms, etc.). A data collection system has been installed in order to test the suitability of OGC Sensor Web Enablement services, exploiting in particular the Sensor Observation Service (SOS) and the associated SensorML and O&M standards (http://geosk.ve.ismar.cnr.it). The toweris also part of the The Aerosol Robotic Network (AERONET), originally developed to evaluate aerosol optical properties and validate satellite retrievals of those properties at various scales with measurements from worldwide distributed autonomous sun photometers Most of the available data are also used to validate operational and research numerical models employed in the area, among which the Italian AdriaROMS 4.0 and NA-COAWST systems, the Slovenian NAPOM and atmosphere-ocean two-way coupled systems, and are related to other existing coastal observatory sites (e.g. the PALOMA buoy in Trieste, http://www.ts.ismar.cnr.it; CNR buoys S1 and E1, http://s1.bo.ismar.cnr.it; the VIDA buoy in Piran, http://buoy.mbss.org). Detailed intercomparisons with the output of meteorological and wave models has allowed a keen correction of the meteorological output, leading to the best wave forecast systems available in the Adriatic and Mediterranean Sea (http://ricerca.ismar.cnr.it/MODELLI/ONDE_MED_ITALIA/page-html/nettuno/NETTUNO2.html). Last but not least, "Acqua Alta" represents a privileged facility for testing "state of the art" ocean technology systems. For

  4. An observatory system for physical and biogeochemical parameters in the northern Adriatic Sea: the "Acqua Alta" oceanographic platform

    NASA Astrophysics Data System (ADS)

    Benetazzo, Alvise; Barbariol, Francesco; Bastianini, Mauro; Bergamasco, Andrea; Bergamasco, Filippo; Bernardi Aubry, Fabrizio; Bertotti, Luciana; Bonaldo, Davide; Cavaleri, Luigi; Carniel, Sandro; Falcieri, Francesco M.; Finotto, Stefania; Lester, Graham; Licer, Matjaz; Malacic, Vlado; Minuzzo, Tiziano; Sclavo, Mauro

    2015-04-01

    during winter 2012. Biological (phyto- and zooplankton) and chemical (dissolved nutrients) measurements are routinely acquired at "Acqua Alta", with periodic sampling on the water column within the Italian Long Term Ecological Research (LTER) network. Two high-resolution webcams have been installed on the submerged structures at -3m and -15m. The main aim is the evaluation of ichthyologic populations of the area for long-term ecological studies, and the real-time images represent a valuable tool as early-warning systems (large mucus aggregates, jellyfish swarms, etc.). A data collection system has been installed in order to test the suitability of OGC Sensor Web Enablement services, exploiting in particular the Sensor Observation Service (SOS) and the associated SensorML and O&M standards (http://geosk.ve.ismar.cnr.it). The toweris also part of the The Aerosol Robotic Network (AERONET), originally developed to evaluate aerosol optical properties and validate satellite retrievals of those properties at various scales with measurements from worldwide distributed autonomous sun photometers Most of the available data are also used to validate operational and research numerical models employed in the area, among which the Italian AdriaROMS 4.0 and NA-COAWST systems, the Slovenian NAPOM and atmosphere-ocean two-way coupled systems, and are related to other existing coastal observatory sites (e.g. the PALOMA buoy in Trieste, http://www.ts.ismar.cnr.it; CNR buoys S1 and E1, http://s1.bo.ismar.cnr.it; the VIDA buoy in Piran, http://buoy.mbss.org). Detailed intercomparisons with the output of meteorological and wave models has allowed a keen correction of the meteorological output, leading to the best wave forecast systems available in the Adriatic and Mediterranean Sea (http://ricerca.ismar.cnr.it/MODELLI/ONDE_MED_ITALIA/page-html/nettuno/NETTUNO2.html). Last but not least, "Acqua Alta" represents a privileged facility for testing "state of the art" ocean technology systems. For

  5. Surface connection between different areas in Mediterranean Sea derived from drifter data

    NASA Astrophysics Data System (ADS)

    Celentano, Paolo; Carlson, Daniel F.; Falco, Pierpaolo; Zambianchi, Enrico

    2016-04-01

    The surface connection of five study areas in the Mediterranean Sea (Sicily Strait, Gulf of Lyon, Ionian Sea, Alborán Sea and Crete Passage) is studied by looking at the statistical properties of near-surface lagrangian trajectories. The choice of the areas is due to the geographical distribution of data and the key role of these sub-basins in the dynamics of the Mediterranean. We used Lagrangian drifter data taken from the Mediterranean Surface Velocity Programme (http://nettuno.ogs.trieste.it/sire/medsvp/). The most common surface drifter used is the CODE-type drifter (Davis, 1985), designed to follow the vertical average velocity of the upper 1 m layer of the water column. The dataset consist of 1547 trajectories, deployed between 1986 and 2015 in all Mediterranean sub basins. By examining the drifter paths through the study areas, we computed transit and residence time, pseudo-Eulerian statistics and connection probabilities. Given the small number of drifters and the non-normal distribution of transit times, it is possible to use a bootstrap method (Efron and Tibshirani, 1986) to estimate the average transit time. In particular, we divided it into forward and backward transit times to consider the time taken by drifters respectively, from the exit of study area to end of its trajectory and from the deployment position to the study area. The main results indicate that the transit time between Sicily Strait and coast of Libya is about 83-103 days and between the Strait and the Gulf of Lyon is approximately 134 days. The time to reach the Adriatic Sea from the Ionian is around 30-40 days; the drifters take around 70 days to go from Alborán Sea to Sardinia channel and 43 days between Crete and the Ionian Sea. The Ionian Sea due has the highest number of drifter trajectories and the highest residence time, about 42 days. Also the Crete Passage has a high value of residence time, approximately 35 days; the other study areas are characterized by residence times of

  6. Spatio-temporal variability of phytoplankton dimensional classes in the Mediterranean Sea from satellite data

    NASA Astrophysics Data System (ADS)

    Sammartino, Michela; Di Cicco, Annalisa; Marullo, Salvatore; Santoleri, Rosalia

    2016-04-01

    coastal areas, such as the North Adriatic Sea, micro-phytoplankton fraction on Chl a is constant, all over the year. On contrary, the contribution of nano-phytoplankton seems to be quite constant (30-40%) over the basin, with higher values in the western basin. At sub-basin scale, the largest interannual variability occurs in specific areas, e.g. Northwestern Mediterranean Sea, influenced by physical processes, which strongly control the nutrients availability. In absence of sufficient in situ data of community composition, our analysis underlines the potential use of ocean colour data for monitoring the phytoplankton assemblage in the Mediterranean Sea.

  7. Cyclone contribution to the Mediterranean Sea water budget

    NASA Astrophysics Data System (ADS)

    Flaounas, E.; Di Luca, A.; Drobinski, P.; Mailler, S.; Arsouze, T.; Bastin, S.; Beranger, K.; Lebeaupin Brossier, C.

    2016-02-01

    This paper analyzes the impact of cyclones to the atmospheric components on the Mediterranean Sea Water Budget, namely the cyclones contribution to precipitation and evaporation over the Mediterranean Sea. Three regional simulations were performed with the WRF model for the period 1989-2008. The model was run (1) as a standalone model, (2) coupled with the oceanic model NEMO-MED12 and (3) forced by the smoothed Sea Surface Temperature (SST) fields from the second simulation. Cyclones were tracked in all simulations, and their contribution to the total rainfall and evaporation was quantified. Results show that cyclones are mainly associated with extreme precipitation, representing more than 50 % of the annual rainfall over the Mediterranean Sea. On the other hand, we found that cyclone-induced evaporation represents only a small fraction of the annual total, except in winter, when the most intense Mediterranean cyclones take place. Despite the significant contribution of cyclones to rainfall, our results show that there is a balance between cyclone-induced rainfall and evaporation, suggesting a weak net impact of cyclones on the Mediterranean Sea water budget. The sensitivity of our results with respect to rapid SST changes during the development of cyclones was also investigated. Both rainfall and evaporation are affected in correlation with the SST response to the atmosphere. In fact, air feedbacks to the Mediterranean Sea during the cyclones occurrence were shown to cool down the SST and consequently to reduce rainfall and evaporation at the proximity of cyclone centers.

  8. Phylogenetic relationships and demographic histories of the Atherinidae in the Eastern Atlantic and Mediterranean Sea re-examined by Bayesian inference.

    PubMed

    Pujolar, J M; Zane, L; Congiu, L

    2012-06-01

    The aim of our study is to examine the phylogenetic relationship, divergence times and demographic history of the five close-related Mediterranean and North-eastern Atlantic species/forms of Atherina using the full Bayesian framework for species tree estimation recently implemented in ∗BEAST. The inference is made possible by multilocus data using three mitochondrial genes (12S rRNA, 16S rRNA, control region) and one nuclear gene (rhodopsin) from multiple individuals per species available in GenBank. Bayesian phylogenetic analysis of the complete gene dataset produced a tree with strong support for the monophyly of each species, as well as high support for higher level nodes. An old origin of the Atherina group was suggested (19.2 MY), with deep split events within the Atherinidae predating the Messinian Salinity Crisis. Regional genetic substructuring was observed among populations of A. boyeri, with AMOVA and MultiDimensional Scaling suggesting the existence of five groupings (Atlantic/West Mediterranean, Adriatic, Greece, Black Sea and Tunis). The level of subdivision found might be consequence of the hydrographic isolation within the Mediterranean Sea. Bayesian inference of past demographic histories showed a clear signature of demographic expansion for the European coast populations of A. presbyter, possibly linked to post-glacial colonizations, but not for the Azores/Canary Islands, which is expected in isolated populations because of the impossibility of finding new habitats. Within the Mediterranean, signatures of recent demographic expansion were only found for the Adriatic population of A. boyeri, which could be associated with the relatively recent emergence of the Adriatic Sea. PMID:22425706

  9. Response of the Mediterranean Sea thermohaline circulation to observed changes in the winter wind stress field in the period 1980-1993

    NASA Astrophysics Data System (ADS)

    Samuel, Sarah; Haines, Keith; Josey, Simon; Myers, Paul G.

    1999-04-01

    This paper seeks to model changes in deep water production in the eastern Mediterranean induced by changes in winter wind stress. An analysis of individual monthly wind stress fields over the Mediterranean for 1980-1993 from the SOC flux data set shows that an intensification of the winter mean (mainly January) wind stress over the Aegean Sea and Levantine basin occurred in the latter half of this period. A weakening of the Mistral occurred at the same time. Two monthly wind stress climatologies were created using the 1980-1987 and 1988-1993 periods, and these were used to force an ocean general circulation model of the Mediterranean, with climatological surface T, S relaxation. The Levantine intermediate water (LIW) dispersal path in the Ionian is altered in the 1988-1993 experiment with no pathway to the Adriatic and, consequently, greatly reduced exchange at Otranto and a collapse in Adriatic deep water formation. In contrast, there is an increased exchange of LIW at the Cretan arc straits and enhanced Aegean deep water production in the 1988-1993 experiment. Much more Aegean water exits into the Levantine and Ionian basins as is shown by an east-west cross section south of Crete, along a similar path to the Meteor cruise in 1995. Changes in air-sea fluxes are diagnosed from the model showing a small increase in wintertime cooling over the Aegean and reduced cooling over the Adriatic after 1987. While the changes in air-sea fluxes are probably underrepresented by this simulation, the large changes induced by the wind forcing suggest this could be a mechanism in the altered thermohaline state of the eastern Mediterranean since 1987.

  10. Characterization of aerosol episodes in the greater Mediterranean Sea area from satellite observations (2000-2007)

    NASA Astrophysics Data System (ADS)

    Gkikas, A.; Hatzianastassiou, N.; Mihalopoulos, N.; Torres, O.

    2016-03-01

    An algorithm able to identify and characterize episodes of different aerosol types above sea surfaces of the greater Mediterranean basin (GMB), including the Black Sea and the Atlantic Ocean off the coasts of Iberia and northwest Africa, is presented in this study. Based on this algorithm, five types of intense (strong and extreme) aerosol episodes in the GMB are identified and characterized using daily aerosol optical properties from satellite measurements, namely MODIS-Terra, Earth Probe (EP)-TOMS and OMI-Aura. These aerosol episodes are: (i) biomass-burning/urban-industrial (BU), (ii) desert dust (DD), (iii) dust/sea-salt (DSS), (iv) mixed (MX) and (v) undetermined (UN). The identification and characterization is made with our algorithm using a variety of aerosol properties, namely aerosol optical depth (AOD), Ångström exponent (α), fine fraction (FF), effective radius (reff) and Aerosol Index (AI). During the study period (2000-2007), the most frequent aerosol episodes are DD, observed primarily in the western and central Mediterranean Sea, and off the northern African coasts, 7 times/year for strong episodes and 4 times/year for extreme ones, on average. The DD episodes yield 40% of all types of strong aerosol episodes in the study region, while they account for 71.5% of all extreme episodes. The frequency of occurrence of strong episodes exhibits specific geographical patterns, for example the BU are mostly observed along the coasts of southern Europe and off the Atlantic coasts of Portugal, the MX episodes off the Spanish Mediterranean coast and over the Adriatic and northern Aegean Sea, while the DSS ones over the western and central Mediterranean Sea. On the other hand, the extreme episodes for all but DD aerosol display more patchy spatial patterns. The strong episodes exhibit AOD at 550 nm as high as 1.6 in the southernmost parts of central and eastern Mediterranean Sea, which rise up to 5 for the extreme, mainly DD and DSS, episodes. Although more

  11. Spatial variations of scavenging rates within the central and northern Adriatic Sea: Use of U-Th disequilibria

    SciTech Connect

    Hamilton, T.; Heilmann, J.; Fowler, S.; Miquel, J.C.

    1996-04-01

    Dissolved and particulate concentrations of {sup 234}Th, {sup 210}Pb and {sup 210}Po were measured in surface waters of the central and northern Adriatic Sea. The half-lives and biogeochemistry of {sup 234}Th (t{sub 1/2} = 24.1 days), {sup 210}Po (t{sub 1/2} = 138.4 days) and {sup 210}Pb (t{sub 1/2} = 22.3 years) are ideal for studying particle dynamics in the upper water column. It has been observed that the residence time of dissolved {sup 234}Th with respect to removal on biogenic particles is inversely proportional to primary productivity and may be used to predict export from or new production in the euphotic zone. Model-derived {sup 234}Th fluxes can also be used to help validate sediment trap collections in the upper water column. The aim of the present study was to gain an insight into the intensity and variability of active scavenging and particle removal processes in the central and northern Adriatic Sea. This semi-enclosed sea is strongly influenced by fresh water runoff from rivers carrying large quantities of dissolved nutrients and suspended particles. These inputs of nutrients and suspended particles are expected to give rise to large biological and biogeochemical gradients across the Continental Shelf and offer a range of environments for studying particle scavenging and removal processes. The authors have examined the relationships between {sup 234}Th scavenging rates and residence times of dissolved and particulate phases as a function of other physical and biological parameters (primary productivity, POC, chlorophyll, C/N and total suspended matter). Particular reference is made to the two contrasting environments of the Adriatic--a eutrophic zone near the Po River outflow and in the largely oligotrophic waters of the Jabuka Pit.

  12. Microbial mechanisms coupling carbon and phosphorus cycles in phosphorus-limited northern Adriatic Sea.

    PubMed

    Malfatti, F; Turk, V; Tinta, T; Mozetič, P; Manganelli, M; Samo, T J; Ugalde, J A; Kovač, N; Stefanelli, M; Antonioli, M; Fonda-Umani, S; Del Negro, P; Cataletto, B; Hozić, A; Ivošević Denardis, N; Zutić, V; Svetličić, V; Mišić Radić, T; Radić, T; Fuks, D; Azam, F

    2014-02-01

    The coastal northern Adriatic Sea receives pulsed inputs of riverine nutrients, causing phytoplankton blooms and seasonally sustained dissolved organic carbon (DOC) accumulation-hypothesized to cause episodes of massive mucilage. The underlying mechanisms regulating P and C cycles and their coupling are unclear. Extensive biogeochemical parameters, processes and community composition were measured in a 64-day mesocosms deployed off Piran, Slovenia. We followed the temporal trends of C and P fluxes in P-enriched (P+) and unenriched (P-) mesocosms. An intense diatom bloom developed then crashed; however, substantial primary production was maintained throughout, supported by tightly coupled P regeneration by bacteria and phytoplankton. Results provide novel insights on post-bloom C and P dynamics and mechanisms. 1) Post-bloom DOC accumulation to 186 μM remained elevated despite high bacterial carbon demand. Presumably, a large part of DOC accumulated due to the bacterial ectohydrolytic processing of primary productivity that adventitiously generated slow-to-degrade DOC; 2) bacteria heavily colonized post-bloom diatom aggregates, rendering them microscale hotspots of P regeneration due to locally intense bacterial ectohydrolase activities; 3) Pi turnover was rapid thus suggesting high P flux through the DOP pool (dissolved organic phosphorus) turnover; 4) Alpha- and Gamma-proteobacteria dominated the bacterial communities despite great differences of C and P pools and fluxes in both mesocosms. However, minor taxa showed dramatic changes in community compositions. Major OTUs were presumably generalists adapted to diverse productivity regimes.We suggest that variation in bacterial ectohydrolase activities on aggregates, regulating the rates of POM→DOM transition as well as dissolved polymer hydrolysis, could become a bottleneck in P regeneration. This could be another regulatory step, in addition to APase, in the microbial regulation of P cycle and the coupling

  13. Benthic activity in sediments of the northwestern Adriatic Sea: sediment oxygen consumption, macro- and meiofauna dynamics

    NASA Astrophysics Data System (ADS)

    Moodley, Leon; Heip, Carlo H. R.; Middelburg, Jack J.

    1998-12-01

    Benthic activity was examined at three stations (18 m water depth) in the northwestern Adriatic Sea. Carbon mineralisation rates, as based on sediment oxygen consumption rates, ranged from 54 to 89 g C m -2 y -1. The relatively high carbon mineralisation rates, large macrofaunal biomass (9 to 16 g C m -2) and macrofaunal production (11 to 19 g C m -2 y -1) provide evidence of high organic-matter input and intense benthic-pelagic coupling. This is further supported by the high dominance of the suspension-feeding bivalve Corbula gibba, which accounts for 52 to 63% of the total annual macrofaunal biomass production. Although the infaunal distribution of total macrofauna showed a sharp decline in densities and biomass with depth into the sediment, different patterns within the dominant taxa were observed. Whilst the bivalve Corbula gibba and the amphipod Ampelisca sp. were restricted to the surface layer, other species such as the dominant bivalve Mysella sp. and the gastropod Hyala sp. were not confined to a specific depth level and the majority of the populations occurred deeper than 5 cm into the sediment. Bioturbation, based on the occurrence of macrofauna, extended to at least 20 cm. Nematodes and foraminifera together formed 80 to 90% of the meiofaunal community in the upper 5 cm of the sediment. Annual mean densities ranged from 3.40 to 6.07×10 6 ind. m -2. Maximum abundance of meiofauna was not encountered at the station where maximum macrofaunal activity was recorded, and this could reflect the negative effect of biological interaction on meiofaunal densities in areas that have a high food supply.

  14. Post-Roman sea-level changes on Pag Island (Adriatic Sea): Dating Croatia's "enigmatic" coastal notch?

    NASA Astrophysics Data System (ADS)

    Marriner, Nick; Morhange, Christophe; Faivre, Sanja; Flaux, Clément; Vacchi, Matteo; Miko, Slobodan; Dumas, Vincent; Boetto, Giulia; Radic Rossi, Irena

    2014-09-01

    The presence of a regional-wide notch (45 to 115 cm below present biological mean sea level [BMSL]) along the Adriatic coast of Croatia, at a string of sites between Zadar and Rijeka, provides evidence for a rapid but poorly constrained subsidence event(s) after Roman times. For more than a century, this geomorphological tidal level indicator has attracted rich scientific debate but many unresolved questions remain. In this paper, we present new results from Caska Bay (Pag Island) looking at notch morphology and Holocene salt-marsh stratigraphy to constrain the chronology of this crustal deformation on Pag Island. The typical salt-marsh stratigraphy comprises low to high salt-marsh muds interjected by an unconformable marine layer (which lies between - 50 and - 100 cm BMSL) consistent with an abrupt transgression. The palaeoecological record shows an abrupt shift in assemblages across the salt-marsh mud-sand sediment contact translating abrupt coastal changes. Geochronological data constrain this event to around 1000 to 1200 cal. AD. The altitude of the layer is coeval with the submerged notch attested on limestone cliffs around the bay. The U-shape of the notch profile, coupled with the sharp palaecological contacts and submerged Roman pier, implies that sea-level rise was episodic and not gradual as suggested by regional numerical models. Together, our findings shed new light on the chronology of the "enigmatic" Croatian notch on the island of Pag, and highlight the need to couple geomorphological studies of rocky coasts with high-resolution sediment records.

  15. Developing a robust tephrochronological framework for Late Quaternary marine records in the Southern Adriatic Sea: new data from core station SA03-11

    NASA Astrophysics Data System (ADS)

    Matthews, I. P.; Trincardi, F.; Lowe, J. J.; Bourne, A. J.; MacLeod, A.; Abbott, P. M.; Andersen, N.; Asioli, A.; Blockley, S. P. E.; Lane, C. S.; Oh, Y. A.; Satow, C. S.; Staff, R. A.; Wulf, S.

    2015-06-01

    Tephra layers are assuming an increasingly important role in the dating and correlation of Late Quaternary marine sequences. Here we demonstrate their potential by reporting a new study of the sediment sequence of marine core SA03-11, recovered from the Southern Adriatic Sea, which spans the last c. 39 ka. A total of 28 discrete tephra layers are reported from this sequence, 10 of which are visible in the core and a further 18 are non-visible cryptotephra layers. These have been analysed using more than 1400 WDS-EPMA measurements of glass chemistry and results have been compared with published chemical measurements obtained from relevant proximal and distal sites which preserve eruptive material dating to within the same time interval. The data show that a high proportion of the layers originate from the Campi Flegrei volcanic field but more distinctive layers are sourced from Vesuvius, the Aeolian Islands and Vulcano, and these provide key marker horizons. The results show that the sequence extends in time to the Campanian Ignimbrite at the base, that a number of the layers have robust age estimates that permit a better constrained age-depth model to be constructed for the sequence, and that the potential exists for importing terrestrially-based age estimates into marine contexts, thereby circumventing problems of incorporating reservoir uncertainties associated with marine radiocarbon dates. The WDS-EPMA dataset generated here also provides important new data that constrain key Late Quaternary tephra layers in the central Mediterranean region.

  16. Recent nutrient dynamics in the Mediterranean Sea

    NASA Astrophysics Data System (ADS)

    Lee, Kitack; Moon, Ji-Young

    2016-04-01

    The concentrations of nitrate (N) and phosphate (P), and the N:P ratio in the upper water column of the Mediterranean Sea (MED) were examined using observational data (~173,000 data points) collected since 1980s. The observed trends were found to distinctly evolve in the western and eastern MED. In the western MED the N and P concentrations have rapidly increased over time and was broadly consistent with the riverine input history from the populated areas surrounding the western MED. Contrarily, the N and P concentrations in the eastern MED markedly increased up until the mid-1995 and briefly remained high between 1995 and 2000. The N concentration rapidly decreased thereafter. In particular, the three-phase temporal transition of N and P in the eastern MED (increase-constant-decline) was more consistent with the emission history of pollutant nitrogen from the western European continent, in which regulation of emissions of pollutant nitrogen has been in place since 1970s. Our analysis implies that the recent N dynamics in the upper MED appeared to be sensitive to input dynamics of anthropogenic N, via atmospheric deposition and river. This conclusion is further strengthened by good agreement between the integrated rate of increase in the upper-water N inventory and the total anthropogenic N input during the past 30 years.

  17. Analysis of coastal sea-level station records and implications for tsunami monitoring in the Adriatic Apulia region, southern Italy

    NASA Astrophysics Data System (ADS)

    Bressan, Lidia; Tinti, Stefano; Tallarico, Andrea

    2015-04-01

    The region of Apulia, southern Italy, was theater of one of the largest tsunami disaster in Italian history (the 30 July 1627 event) and is considered to be exposed to tsunami hazard coming from local Italian sources as well as from sources on the eastern side of the Adriatic and from the Ionian sea, including the Hellenic Arc earthquakes. Scientific interest for tsunami studies and monitoring in the region is only recent and this theme was specifically addressed by the international project OTRIONS, coordinated by the University of Bari. In the frame of this project the University of Bologna contributed to the analysis of the tsunami hazard and to the evaluation of the regional tide-gauge network with the scope of assessing its adequacy for tsunami monitoring. This latter is the main topic of the present work. In eastern Apulia, facing the Adriatic sea, the sea-level data network is sufficiently dense being formed of stations of the Italian tide-gauge network (Rete Mareografica Nazionale, RMN), of four additional stations operated by the Apulia Port Authority (in Brindisi, Ischitella, Manfredonia and Porto Cesareo) and of two more stations that were installed in the harbours of Barletta and Monopoli in the frame of the project OTRIONS with real-time data transmission and 1-sec sampling period. Pre-processing of the sea-level data of these stations included quality check and spectral analysis. Where the sampling rate was adequate, the records were also examined by means of the specific tools provided by the TEDA package. This is a Tsunami Early Detection Algorithm, developed by the Tsunami Research Team of the University of Bologna, that allows one to characterize the sea-level background signal in the typical tsunami frequency window (from 1 to several minutes) and consequently to optimize TEDA parameters for an efficient tsunami detection. The results of the analysis show stability of the spectral content and seasonal variations.

  18. Comparative growth and toxin profile of cultured Ostreopsis ovata from the Tyrrhenian and Adriatic Seas.

    PubMed

    Guerrini, Franca; Pezzolesi, Laura; Feller, Andrea; Riccardi, Manuela; Ciminiello, Patrizia; Dell'Aversano, Carmela; Tartaglione, Luciana; Dello Iacovo, Emma; Fattorusso, Ernesto; Forino, Martino; Pistocchi, Rossella

    2010-01-01

    Massive blooms of the benthic dinoflagellate Ostreopsis ovata Fukuyo have recently occurred along the whole Italian coastlines, both Tyrrhenian and Adriatic, resulting sometimes in benthonic biocenosis sufferings and, occasionally, in human health problems. In this work, two strains of O. ovata collected in 2006 along the Adriatic and Tyrrhenian coastlines and grown in culture were studied to characterize their growth and toxin profile. The two strains showed different cell volumes, the Adriatic strain being nearly twice bigger than the Tyrrhenian, but they had similar slow growth rates. Liquid chromatography-mass spectrometry (LC-MS) analyses indicated that both strains produce putative palytoxin (pPLTX) and ovatoxin-a (OVTX-a), a palytoxin-like compound presenting 2 oxygen atoms less than palytoxin. Toxin content was determined at the end of the stationary and exponential growth phases and reached the highest value in the Adriatic strain at the end of the stationary phase, with concentrations of 353.3 microg l(-1) for OVTX-a and 30.4 microg l(-1) for pPLTX. Toxin released in the growth medium was also measured and resulted to be the highest at the end of the stationary phase, suggesting that a long lasting bloom could enhance the toxin content in the water and cause toxic effects in people inhaling the aerosol. PMID:19638281

  19. Patterns in nematode community during and after experimentally induced anoxia in the northern Adriatic Sea.

    PubMed

    Taheri, Mehrshad; Grego, Mateja; Riedel, Bettina; Vincx, Magda; Vanaverbeke, Jan

    2015-09-01

    The effect of short and long-term induced anoxia on a benthic nematode community and its potential for recovery after reoxygenation were investigated in an in situ experiment on a silty-sand bottom in the Gulf of Trieste, the northern Adriatic Sea. Anoxia was created artificially by three underwater benthic Plexiglas chambers at a depth of 24 m. Treatments lasted for 2, 23 and 307 days. Control samples (Normoxia) were taken on 3 (Normoxia 1) and 25 (Normoxia 2) August 2010 outside the chambers (4-5 m further). After opening the chambers, recovery cores were taken after 7 days (Anoxia 2D), 30 days (Anoxia 23D) and 90 days (Anoxia 307D). Our results revealed that short-term anoxia (Anoxia 2D) did not affect nematode total density and diversity, community structure and their vertical distribution in the sediment. However, total and vertical nematode density, species richness and diversity decreased at 23 days and decreased further at 307 days anoxia. Some nematode species like Metalinhomoeus effilatus, Paralinhomoeus caxinus and Terschellingia longicaudata even survived at 307 days anoxia treatment. Our results also demonstrated that nematode community exposed to 23 days anoxia did not recover after 30 days sediment reoxygenation but, a full recovery was observed after 90 days for nematode community exposed to 307 days anoxia. Feeding type contribution (functional aspect) of the nematode community also changed at the anoxia treatments and during the recovery process. This change was most drastic at the Anoxia 23D and 307D treatments. At both Normoxia and Anoxia 2D treatments, selective deposit feeders (1A), non-selective deposit feeders (1B) and epistrate (diatom) feeders (2A) nematodes were observed in the dominant nematode community. Epistrate feeders disappeared from in the Anoxia 23D treatment epistrate and also selective deposit feeders did not belong to the dominant nematode species in the Anoxia 307D treatment. After the recovery process, epistrate feeders

  20. The Mediterranean and Black Sea fisheries at risk from overexploitation.

    PubMed

    Tsikliras, Athanassios C; Dinouli, Anny; Tsiros, Vasileios-Zikos; Tsalkou, Eleni

    2015-01-01

    The status of the Mediterranean and Black Sea fisheries was evaluated for the period 1970-2010 on a subarea basis, using various indicators including the temporal variability of total landings, the number of recorded stocks, the mean trophic level of the catch, the fishing-in-balance index and the catch-based method of stock classification. All indicators confirmed that the fisheries resources of the Mediterranean and Black Sea are at risk from overexploitation. The pattern of exploitation and the state of stocks differed among the western (W), central (C) and eastern (E) Mediterranean subareas and the Black Sea (BS), with the E Mediterranean and BS fisheries being in a worst shape. Indeed, in the E Mediterranean and the BS, total landings, mean trophic level of the catch and fishing-in-balance index were declining, the cumulative percentage of overexploited and collapsed stocks was higher, and the percentage of developing stocks was lower, compared to the W and C Mediterranean. Our results confirm the need for detailed and extensive stock assessments across species that will eventually lead to stocks recovering through conservation and management measures. PMID:25793975

  1. The Mediterranean and Black Sea Fisheries at Risk from Overexploitation

    PubMed Central

    Tsikliras, Athanassios C.; Dinouli, Anny; Tsiros, Vasileios-Zikos; Tsalkou, Eleni

    2015-01-01

    The status of the Mediterranean and Black Sea fisheries was evaluated for the period 1970-2010 on a subarea basis, using various indicators including the temporal variability of total landings, the number of recorded stocks, the mean trophic level of the catch, the fishing-in-balance index and the catch-based method of stock classification. All indicators confirmed that the fisheries resources of the Mediterranean and Black Sea are at risk from overexploitation. The pattern of exploitation and the state of stocks differed among the western (W), central (C) and eastern (E) Mediterranean subareas and the Black Sea (BS), with the E Mediterranean and BS fisheries being in a worst shape. Indeed, in the E Mediterranean and the BS, total landings, mean trophic level of the catch and fishing-in-balance index were declining, the cumulative percentage of overexploited and collapsed stocks was higher, and the percentage of developing stocks was lower, compared to the W and C Mediterranean. Our results confirm the need for detailed and extensive stock assessments across species that will eventually lead to stocks recovering through conservation and management measures. PMID:25793975

  2. Setting Priorities for Regional Conservation Planning in the Mediterranean Sea

    PubMed Central

    Micheli, Fiorenza; Levin, Noam; Giakoumi, Sylvaine; Katsanevakis, Stelios; Abdulla, Ameer; Coll, Marta; Fraschetti, Simonetta; Kark, Salit; Koutsoubas, Drosos; Mackelworth, Peter; Maiorano, Luigi; Possingham, Hugh P.

    2013-01-01

    Spatial prioritization in conservation is required to direct limited resources to where actions are most urgently needed and most likely to produce effective conservation outcomes. In an effort to advance the protection of a highly threatened hotspot of marine biodiversity, the Mediterranean Sea, multiple spatial conservation plans have been developed in recent years. Here, we review and integrate these different plans with the goal of identifying priority conservation areas that represent the current consensus among the different initiatives. A review of six existing and twelve proposed conservation initiatives highlights gaps in conservation and management planning, particularly within the southern and eastern regions of the Mediterranean and for offshore and deep sea habitats. The eighteen initiatives vary substantially in their extent (covering 0.1–58.5% of the Mediterranean Sea) and in the location of additional proposed conservation and management areas. Differences in the criteria, approaches and data used explain such variation. Despite the diversity among proposals, our analyses identified ten areas, encompassing 10% of the Mediterranean Sea, that are consistently identified among the existing proposals, with an additional 10% selected by at least five proposals. These areas represent top priorities for immediate conservation action. Despite the plethora of initiatives, major challenges face Mediterranean biodiversity and conservation. These include the need for spatial prioritization within a comprehensive framework for regional conservation planning, the acquisition of additional information from data-poor areas, species or habitats, and addressing the challenges of establishing transboundary governance and collaboration in socially, culturally and politically complex conditions. Collective prioritised action, not new conservation plans, is needed for the north, western, and high seas of the Mediterranean, while developing initial information

  3. Setting priorities for regional conservation planning in the Mediterranean Sea.

    PubMed

    Micheli, Fiorenza; Levin, Noam; Giakoumi, Sylvaine; Katsanevakis, Stelios; Abdulla, Ameer; Coll, Marta; Fraschetti, Simonetta; Kark, Salit; Koutsoubas, Drosos; Mackelworth, Peter; Maiorano, Luigi; Possingham, Hugh P

    2013-01-01

    Spatial prioritization in conservation is required to direct limited resources to where actions are most urgently needed and most likely to produce effective conservation outcomes. In an effort to advance the protection of a highly threatened hotspot of marine biodiversity, the Mediterranean Sea, multiple spatial conservation plans have been developed in recent years. Here, we review and integrate these different plans with the goal of identifying priority conservation areas that represent the current consensus among the different initiatives. A review of six existing and twelve proposed conservation initiatives highlights gaps in conservation and management planning, particularly within the southern and eastern regions of the Mediterranean and for offshore and deep sea habitats. The eighteen initiatives vary substantially in their extent (covering 0.1-58.5% of the Mediterranean Sea) and in the location of additional proposed conservation and management areas. Differences in the criteria, approaches and data used explain such variation. Despite the diversity among proposals, our analyses identified ten areas, encompassing 10% of the Mediterranean Sea, that are consistently identified among the existing proposals, with an additional 10% selected by at least five proposals. These areas represent top priorities for immediate conservation action. Despite the plethora of initiatives, major challenges face Mediterranean biodiversity and conservation. These include the need for spatial prioritization within a comprehensive framework for regional conservation planning, the acquisition of additional information from data-poor areas, species or habitats, and addressing the challenges of establishing transboundary governance and collaboration in socially, culturally and politically complex conditions. Collective prioritised action, not new conservation plans, is needed for the north, western, and high seas of the Mediterranean, while developing initial information-based plans

  4. Microbial community genomics in eastern Mediterranean Sea surface waters.

    PubMed

    Feingersch, Roi; Suzuki, Marcelino T; Shmoish, Michael; Sharon, Itai; Sabehi, Gazalah; Partensky, Frédéric; Béjà, Oded

    2010-01-01

    Offshore waters of the eastern Mediterranean Sea are one of the most oligotrophic regions on Earth in which the primary productivity is phosphorus limited. To study the unexplored function and physiology of microbes inhabiting this system, we have analyzed a genomic library from the eastern Mediterranean Sea surface waters by sequencing both termini of nearly 5000 clones. Genome recruitment strategies showed that the majority of high-scoring pairs corresponded to genomes from the Alphaproteobacteria (SAR11-like and Rhodobacterales), Cyanobacteria (Synechococcus and high-light adapted Prochlorococcus) and diverse uncultured Gammaproteobacteria. The community structure observed, as evaluated by both protein similarity scores or metabolic potential, was similar to that found in the euphotic zone of the ALOHA station off Hawaii but very different from that of deep aphotic zones in both the Mediterranean Sea and the Pacific Ocean. In addition, a strong enrichment toward phosphate and phosphonate uptake and utilization metabolism was also observed. PMID:19693100

  5. A Coupled Atmosphere-Ocean modelling system to investigate the exceptional Winter 2012 conditions in the Northern Adriatic Sea

    NASA Astrophysics Data System (ADS)

    Ricchi, Antonio; Marcello Miglietta, M.; Benetazzo, Alvise; Warner, John C.; Zambon, Joseph B.; Bonaldo, Davide; Falcieri, Francesco M.; Bergamasco, Andrea; Sclavo, Mauro; Carniel, Sandro

    2014-05-01

    During late January and early February 2012, a persistent cyclonic circulation associated with an exceptional cold anomaly dominated the Mediterranean region. Among the resulting effects, the northern Adriatic sea basin (NA) experienced a very large energy losses, mostly related to the intense and cold Bora winds blowing from north-east. Sea water temperature along the Italian coast dropped down to 6 °C, while part of the Venice lagoon got frozen. These series of exceptionally cold air outbreak episodes, as well as their effects on the NA circulation and dense water formation, are investigated by means of the Coupled Ocean-Atmosphere-Wave-Sediment Transport (COAWST) Modeling System, where the oceanographic model ROMS, the atmospheric model WRF and the wave model SWAN are coupled via MCT. In this specific application to the NA sea configuration, lasting from January 23 to February 23, 2012, particular emphasis was devoted to the analysis of the atmosphere-ocean-waves interactions. First, we employ the "stand alone" WRF atmospheric model in 4 different modes ("zero mode", i.e. using the skin temperature from the global atmospheric model without updating in the Sea Surface Temperature (SST); "static mode", i.e. retaining the January 23 radiometer SST; "dynamic mode", updating every 6 hours the SST as derived from radiometer data at 0.83 deg resolution; "OML mode", as above, but using a simple Ocean Mixed Layer model available within WRF to predict the temperature evolution). Second, the WRF-ROMS one-way forced case is analyzed, where no feedbacks to the atmosphere are provided from the ocean model ROMS, but momentum and heat fluxes are determined by WRF model. Then, the WRF-ROMS two-way coupled case is implemented (where the atmosphere model exchanges momentum and heat, and the ocean model exchanges SST with the Atmospheric model). Finally, the WRF-ROMS-SWAN two-way coupled case for waves-ocean-atmosphere is performed, where common variables are exchanged every 1200

  6. Contamination by polychlorinated biphenyls (PCBs) in striped dolphins (Stenella coeruleoalba) from the Southeastern Mediterranean Sea.

    PubMed

    Storelli, Maria Maddalena; Barone, Grazia; Giacominelli-Stuffler, Roberto; Marcotrigiano, Giuseppe Onofrio

    2012-09-01

    Concentrations of polychlorinated biphenyls (PCBs) including dioxin-like PCBs (non-ortho, PCB 77, PCB 126, and PCB 169 and mono-ortho, PCB 105, PCB 118, and PCB 156) were measured in different organs and tissues (melon, blubber, liver, kidney, lung, heart, and muscle tissue) of striped dolphins (Stenella coeruleoalba) from the Eastern Mediterranean Sea (Adriatic Sea). The mean highest levels were in blubber and melon, followed by liver, kidney, lung, heart, and muscle tissue. PCB profiles were similar in all tissues and organs being dominated by the higher chlorinated homologues (hexa-CBs, 55.8-62.1%; penta-CBs, 15.4-20.0%; and hepta-CB PCB 180, 12.7-16.5%). Major PCBs in all tissues were congeners 138 and 153 collectively accounting for 50.6-58.3% of the total PCB concentrations, followed by PCB 101, 105, 118, and 180 constituting from 27.0% to 31.0%. PCB levels were higher in adult males than in adult females. The estimated 2,3,7,8-TCDD toxic equivalents of non- and mono-ortho PCBs were much higher than the threshold level above which adverse effects have been observed in other marine mammals species, suggesting that striped dolphins in this region are at risk for toxic effects. PMID:21960363

  7. Spatio-temporal variability of micro-, nano- and pico-phytoplankton in the Mediterranean Sea from satellite ocean colour data of SeaWiFS

    NASA Astrophysics Data System (ADS)

    Sammartino, M.; Di Cicco, A.; Marullo, S.; Santoleri, R.

    2015-02-01

    The seasonal and year-to-year variability of the spatial distribution of the Phytoplankton Size Classes (PSCs) has been examined in the Mediterranean Sea using the entire time series of Sea-viewing Wide Field-of-view Sensor (SeaWiFS) space observations (1998 to 2010). PSCs daily maps have been determined using an empirical model based on a synoptic relationship between surface chlorophyll a and diagnostic pigments referred to different taxonomic groups. The validation of model PSCs estimates using a Mediterranean HPLC pigments dataset revealed that the model is able to correctly detect the contribution of pico-, nano- and micro-phytoplankton to TChl a. The analysis of micro-, nano- and pico-phytoplankton satellite time series (1998-2010) describes quantitatively the seasonal and inter-annual variability of the spatial distribution of the algal assemblage structure over the basin. The analysis reveals that in most of the Mediterranean Sea the main contribution to the chlorophyll a all around the year comes from the pico-phytoplankton component, above all in poor nutrient conditions. Regions with different and peculiar features are the northwestern Mediterranean Sea, the Alborán Sea and several coastal areas, such as the north Adriatic Sea. In these areas, local interactions between physical and biological components modulate the competition between the three phytoplankton size classes. It results that, during the spring bloom season, micro-phytoplankton dominates in areas of intense vertical winter mixing and deep/intermediate water formation; while, in coastal areas, micro-phytoplankton dominates in all seasons, thanks to the nutrients supply that comes from the terrestrial inputs. In the Alborán Sea, in which the Atlantic inflow modulates the nutrient availability, any predominance of one class over the other two has been observed. Nano-phytoplankton component instead remains widespread over the entire basin along the year, and its contribution to the TChl a is

  8. An ecological model of the Northern and Central Adriatic Sea: Analysis of ecosystem structure and fishing impacts

    NASA Astrophysics Data System (ADS)

    Coll, Marta; Santojanni, Alberto; Palomera, Isabel; Tudela, Sergi; Arneri, Enrico

    2007-08-01

    A trophic mass-balance model was developed to characterise the food web structure and functioning of the Northern and Central Adriatic Sea and to quantify the ecosystem impacts of fishing during the 1990s. Forty functional groups were described, including target and non-target fish and invertebrate groups, and three detritus groups (natural detritus, discards and by-catch of cetaceans and marine turtles). Results highlighted that there was an important coupling between pelagic-benthic production of plankton, benthic invertebrates and detritus. Organisms located at low and medium trophic levels, (i.e. benthic invertebrates, zooplankton and anchovy), as well as dolphins, were identified as keystone groups of the ecosystem. Jellyfish were an important element in terms of consumption and production of trophic flows within the ecosystem. The analysis of trophic flows of zooplankton and detritus groups indirectly underlined the importance of the microbial food web in the Adriatic Sea. Fishing activities inflicted notable impacts on the ecosystem during the 1990s, with a high gross efficiency of the fishery, a high consumption of fishable production, high exploitation rates for various target and non target species, a low trophic level of the catch and medium values of primary production required to sustain the fishery. Moreover, the analysis of Odum's ecological indicators highlighted that the ecosystem was in a low-medium developmental stage. Bottom trawling ( Strascico), mid-water trawling ( Volante) and beam trawling ( Rapido) fleets had the highest impacts on both target and non target ecological groups. On the contrary, purse seining ( Lampara) showed medium to low impacts on the ecosystem; cetaceans, marine turtles and sea birds were not significantly involved in competition with fishing activity.

  9. MEDARGO: A drifting profiler program in the Mediterranean Sea

    NASA Astrophysics Data System (ADS)

    Poulain, P.-M.; Barbanti, R.; Font, J.; Cruzado, A.; Millot, C.; Gertman, I.; Griffa, A.; Molcard, A.; Rupolo, V.; Le Bras, S.; Petit de La Villeon, L.

    2006-11-01

    In the framework of the EU-funded MFSTEP project, autonomous drifting profilers were deployed throughout the Mediterranean Sea to collect temperature and salinity profile data and to measure subsurface currents. The realization of this profiler program in the Mediterranean, referred to as MEDARGO, is described and assessed using data collected between June 2004 and March 2006 (including more than 1500 profiles). Recommendations are provided for the permanent future implementation of MEDARGO in support of operational oceanography in the Mediterranean Sea. More than twenty drifting profilers were deployed from research vessels and ships-of-opportunity in most areas of the Mediterranean. They were all programmed to execute 5-day cycles with drift at a neutral parking depth of 350 m and CTD profiles from either 700 or 2000 m up to the surface. They stayed at the sea surface for about 6 h to be localised by, and transmit the data to, the Argos satellite system. The temperature and salinity data obtained with pumped Sea-Bird CTD instruments were processed and made available to the scientific community and to operational users in near-real time using standard ARGO protocols, and were assimilated into Mediterranean numerical forecasting models. In general, the cycling and sampling characteristics chosen for the MEDARGO profilers were found to be adequate for the Mediterranean. However, it is strongly advised to use GPS and global cellular phone telemetry or the future Argos bi-directional satellite system in order to avoid data compression and losses, for the continuation of the Mediterranean drifting profiler program.

  10. Mapping of decadal middle Adriatic oceanographic variability and its relation to the BiOS regime

    NASA Astrophysics Data System (ADS)

    Mihanović, Hrvoje; Vilibić, Ivica; Dunić, Natalija; Å epić, Jadranka

    2015-08-01

    We analyzed long-term time series of temperature, salinity, and dissolved oxygen (DO) concentrations collected along the Palagruža Sill transect (middle Adriatic) between 1952 and 2010. The data have been mostly collected on seasonal basis, allowing for extraction of seasonal signal from the series. By applying Self-Organizing Maps (SOM) method, a kind of unsupervised neural network method, the processes on a decadal time scale emerged as the most relevant for changes of oceanographic properties in the middle Adriatic area. Sensitivity studies revealed that oceanographic patterns obtained by SOM were not sensitive to shortening of time series, to removal of data from one station or to removal of DO from the analysis. Simultaneous SOM-based mapping of sea surface heights in the northern Ionian Sea, with these heights serving as a proxy for the Adriatic-Ionian Bimodal Oscillating System (BiOS), revealed asymmetry between anticyclonic and cyclonic BiOS patterns and correlated the decadal oscillations in the middle Adriatic with the reversals in the BiOS circulation regimes. These reversals are found to either rapidly change oceanographic properties in the middle Adriatic (e.g., during the Eastern Mediterranean Transient) or to change them with a time lag of 2-3 years. The mapped connections may be used for a short-time (a few years) forecasting of the Adriatic oceanographic properties or for mapping future climate decadal oscillations as seen by ocean climate models.

  11. Changing coastal oceanography of the Black Sea II: Mediterranean effluent

    NASA Astrophysics Data System (ADS)

    Tolmazin, D.

    The behavior and physical mechanisms during the Mediterranean flow, entering the Black Sea from the Bosphorus, are described using existing field observations and hydrodynamic models for the vertical and along axis circulation in the strait. Soviet studies in the 1960-1970's showed that a well-defined sill north of the Bosphorus does not prevent the overflow of dense Mediterranean water onto the shelf even during unfavorable conditions (high surface elevation in the Black Sea and strong northerly winds). The stream makes a sharp westward turn after exiting from the strait and then starts its track downward to the shelf slope. Intensive dispersion of the Mediterranean water occurs at a distance of 25-50 km from the strait. Recent laboratory and mathematical models have been reviewed to describe the behavior of the density and current interfaces in the strait and the role of temporary blockage of the dense flow upon the Mediterranean effluent. Two hypothetic physical mechanisms for sill overflow are discussed. One is associated with bifurcation of the coastal flows, approaching the strait orifice, and formation of a diversion zone in the upper layer which facilitates the flow over the sill. Another hypothesis suggests that the sill exercises frictionless rotational hydraulic control in the short, 4 km continuation of the strait channel. Persistent northeasterly or southerly winds can substantially affect the intensity of the Mediterranean effluent by modifying the average flow fields and density structures in the strait. TS-analysis of far-field property distribution shows that the Mediterranean water contributes to the laminated structure of the Black Sea water column. Under average conditions, the Mediterranean waters follow the mainstream of the Black Sea current system along the Turkish coast, reaching the deepest strata in the southeastern corner of the sea. Ongoing Soviet diversions of fresh water from the northern slope of the Black Sea and projected damming

  12. Combined effects of the herbicide terbuthylazine and temperature on different flagellates from the Northern Adriatic Sea.

    PubMed

    Fiori, Emanuela; Mazzotti, Matilde; Guerrini, Franca; Pistocchi, Rossella

    2013-03-15

    The triazinic herbicide terbuthylazine (TBA) is becoming an emergent contaminant in Italian rivers and in coastal and groundwater. A preliminary analysis of the sensitivity of marine flagellates to TBA was performed by monitoring the photosynthetic efficiency of nine species (belonging to the Dinophyceae or Raphidophyceae class) isolated from the Adriatic Sea. Different sensitivity levels for each flagellate were observed and the most sensitive microalgae, based on PSII inhibition, were: Gonyaulax spinifera>Fibrocapsa japonica>Lingulodinium polyedrum while the most resistant were two species belonging to the Prorocentrum genus. Then the response of two microalgae to drivers, such as temperature and terbuthylazine, applied in combination was also investigated. Two potentially toxic flagellates, Prorocentrum minimum and G. spinifera, were exposed, under different temperature conditions (15, 20 and 25°C), to TBA concentrations that did not completely affect PSII. For both flagellates, effects of TBA on algal growth, measured through cell density and carbon analysis, as well as on the photosynthetic activity are reported. All parameters analyzed showed a negative effect of TBA from the exponential phase. TBA effect on algal growth was significantly enhanced at the optimal temperature conditions (20 and 25°C), while no difference between control and herbicide treatments were detected for G. spinifera grown at 15°C, which represented a stress condition for this species. The maximum inhibition of photosynthetic efficiency was found at 20°C for both organisms. Both flagellates increased cell carbon and nitrogen content in herbicide treatments compared to the control, except G. spinifera grown at 15°C. Chlorophyll-a production was increased only in G. spinifera exposed to 5 μg L(-1) of TBA and the effect was enhanced with the increase of temperature. Herbicide-induced variations in cellular components determined changes in cellular carbon:nitrogen (C:N) and

  13. Carbonate system variability in the Gulf of Trieste (North Adriatic Sea)

    NASA Astrophysics Data System (ADS)

    Cantoni, Carolina; Luchetta, Anna; Celio, Massimo; Cozzi, Stefano; Raicich, Fabio; Catalano, Giulio

    2012-12-01

    The seasonal variability of the carbonate system in the waters of the Gulf of Trieste (GoT) was studied at PALOMA station from 2008 to 2009, in order to highlight the effects of biological processes, meteorological forcings and river loads on the dynamics of pHT, CO2 partial pressure (pCO2), dissolved inorganic carbon (DIC), carbonate ion concentration (CO3=), aragonite saturation state (ΩAr) and total alkalinity (AT). During winter, low seawater temperature (9.0 ± 0.4 °C) and a weak biological activity (-10.7 < AOU < 15.7 μmol O2 kg-1) in a homogeneous water column led to the lowest average values of pCO2 (328 ± 19 μatm) and ΩAr (2.91 ± 0.14). In summer, the water column in the area acted as a two-layer system, with production processes prevailing in the upper layer (average AOU = -29.3 μmol O2 kg-1) and respiration processes in the lower layer (average AOU = 26.8 μmol O2 kg-1). These conditions caused the decrease of DIC (50 μmol kg-1) and the increase of ΩAr (1.0) values in the upper layer, whereas opposite trends were observed in the bottom waters. In August 2008, during a hypoxic event (dissolved oxygen DO = 86.9 μmol O2 kg-1), the intense remineralisation of organic carbon caused the rise of pCO2 (1043 μatm) and the decreases of pHT and ΩAr values down to 7.732 and 1.79 respectively. On an annual basis, surface pCO2 was mainly regulated by the pronounced seasonal cycle of seawater temperature. In winter, surface waters in the GoT were under-saturated with respect to atmospheric CO2, thus acting as a sink of CO2, in particular when strong-wind events enhanced air-sea gas exchange (FCO2 up to -11.9 mmol m-2 d-1). During summer, the temperature-driven increase of pCO2 was dampened by biological CO2 uptake, as consequence a slight over-saturation (pCO2 = 409 μatm) turned out. River plumes were generally associated to higher AT and pCO2 values (up to 2859 μmol kg-1 and 606 μatm respectively), but their effect was highly variable in space and time

  14. Spatio-temporal variability of micro-, nano- and pico-phytoplankton in the Mediterranean Sea from satellite ocean colour data of SeaWiFS

    NASA Astrophysics Data System (ADS)

    Sammartino, M.; Di Cicco, A.; Marullo, S.; Santoleri, R.

    2015-09-01

    The seasonal and year-to-year variability of the phytoplankton size class (PSC) spatial distribution has been examined in the Mediterranean Sea by using the entire time series of Sea-viewing Wide Field-of-view Sensor (SeaWiFS) space observations (1998-2010). Daily maps of PSCs have been determined using an empirical model based on a synoptic relationship between surface chlorophyll a and diagnostic pigments referred to different taxonomic groups. The analysis of micro-, nano- and pico-phytoplankton satellite time series (1998-2010) describes, quantitatively, the algal assemblage structure over the basin and reveals that the main contribution to chlorophyll a in most of the Mediterranean Sea comes from the pico-phytoplankton component, especially in nutrient-poor environments. Regions with different and peculiar features are the Northwestern Mediterranean Sea, the Alborán Sea and several coastal areas, such as the North Adriatic Sea. In these areas, local interactions between physical and biological components modulate the composition of the three phytoplankton size classes. It results that, during the spring bloom season, micro-phytoplankton dominates in areas of intense vertical winter mixing and deep/intermediate water formation, while in coastal areas micro-phytoplankton dominates in all seasons because of the nutrient supply from the terrestrial inputs. In the Alborán Sea, where the Atlantic inflow modulates the nutrient availability, any predominance of one class over the other two has been observed. The nano-phytoplankton component instead remains widespread over the entire basin along the year, and its contribution to chlorophyll a is of the order of 30-40 %. The largest inter-annual signal occurs in the Northwestern Mediterranean Sea, driven by the year-to-year variation in intensity and extension of the spring bloom, followed by the Alborán Sea, in which the inter-annual variability is strongly modulated by the Atlantic inflow. In absence of sufficient

  15. Coastal vulnerability and the implications of sea level rise between the cities of Pescara and Ortona (Adriatic Sea - Central Italy)

    NASA Astrophysics Data System (ADS)

    Tarragoni, C.; Bellotti, P.; Caputo, C.; Davoli, L.; Evangelista, S.; Pugliese, F.; Raffi, R.; Lupia Palmieri, E.

    2012-04-01

    Geomorphic processes induce rapid environmental changes especially along the coast that is highly susceptible to them. In addiction, the effects of storm or wave may be amplified by the expected relative sea level rise. In a context, like Italian coast, where the almost part of coast is densely populated and many infrastructures are presents, it is very important to have adequate tools to urban planning like the coastal vulnerability map. In this study the preliminary results of the ongoing SECOA project (Solution for Environmental contrasts in COastal Areas; 7th Framework Program) are presented, with reference to the Adriatic coast between Pescara and Ortona cities, in the Abruzzo region. In this work the same analytical model applied in the Venice Lagoon has been employed (Fontolan, 2001; 2005) involving the evaluation of the effective vulnerability (Ve). Ve is calculated as the difference between the potential vulnerability (Vp) and the defence elements present along the coast (D). (Ve = Vp - D) The data used to measure quantitative features are: high-resolution DEM (LiDAR), satellite images, aero photos, bathymetric profiles and topographic maps. The variables that contribute to the evaluation are: beach amplitude, berm height, seafloor gradient, seafloor evolution, recent and historical shorelines evolution for Vp; height, slope, vegetation cover, presence of passages, incipient dunes and windbreak barriers for the dune and anthropic barriers height. In this context, the potential vulnerability results from the sum of each variable (Vn) per the relative efficacy coefficient (Kn): Vp = V1K1+V2K2+ …VnKn In the same way the defences result from the sum of each kind of defence per the relative efficacy coefficient: D = D1K1+ …. DnKn The coastal area between Pescara and Ortona cities has been segmented in different sectors characterized by homogeneous values of the considered variables and for each of these the Ve values have been calculated and referred to one

  16. Picoplankton community structure before, during and after convection event in the offshore waters of the Southern Adriatic Sea

    NASA Astrophysics Data System (ADS)

    Najdek, M.; Paliaga, P.; Šilović, T.; Batistić, M.; Garić, R.; Supić, N.; Ivančić, I.; Ljubimir, S.; Korlević, M.; Jasprica, N.; Hrustić, E.; Dupčić-Radić, I.; Blažina, M.; Orlić, S.

    2014-05-01

    This paper documents the picoplankton community's response to changes in oceanographic conditions in the period between October 2011 and September 2012 at two stations belonging to the South Adriatic Pit (SAP). The recorded data include the community's abundance, composition, prokaryotic production rates and bacterial metabolic capacity. The sampling period included an intense sea cooling with formation of exceptional, record-breaking dense water. We documented an especially intense winter convection episode that completely diluted the core of Levantine intermediate waters (LIW) in a large area encompassing the SAP's center and its margin. During this convection event the whole picoplankton community had significantly higher abundances with a recorded picoeukaryotic peak at the SAP margin. In the post-convection phase in March, prokaryotic heterotrophic production strongly increased in the entire SAP area (up to 50 times; 456.8 nM C day-1). An autotrophic biomass increase (up to 5 times; 4.86 μg L-1) and a disruption of a close correspondence between prokaryotic heterotrophic biomass production and cell replication rates were observed only in the center of the SAP, which was not under the influence of LIW. At the SAP's margin such an effect was attenuated by LIW, since the waters affected by LIW were characterized by decreased concentrations of dissolved inorganic nitrogen, decreased autotrophic biomasses, and by increased bacterial biomass production balanced with cell replication rates as well as by the domination of Synechococcus among autotrophic picoplankton. The metabolic capacity was lowest in spring when autotrophic biomass largely increased, while the highest levels found in the pre-convection phase (October 2011) suggest that the system was more oligotrophic before than after the convection event. Furthermore, we showed that metabolic capacity is a trait of bacterial community independent of environmental conditions and tightly linked to cell replication

  17. Phosphorus regeneration and burial in near-shore marine sediments (the Gulf of Trieste, northern Adriatic Sea)

    NASA Astrophysics Data System (ADS)

    Ogrinc, N.; Faganeli, J.

    2006-05-01

    According to bioassay studies and high dissolved nutrient N/P ratios in the seawater column, phosphorus (P) is thought to control marine productivity in the northern Adriatic Sea. P in near-shore marine sediments of the Gulf of Trieste, the northernmost part of the Adriatic Sea, was investigated using pore water P distributions, and benthic P flux studies under oxic and anoxic conditions. The data show that P regeneration is up to three-fold more extensive in sediments overlain by oxygen-depleted waters and proceeds in parallel with Fe and Mn enhanced benthic fluxes. It appears from the incubation experiments that degradation of sedimentary organic matter is the main contribution to the flux of P at the sediment-water interface, while the release of phosphate adsorbed on the iron oxide surface is of minor importance. It appears that about 50% of P in the Gulf of Trieste is retained within in the sediments, probably bonded to clay minerals and carbonate grains or precipitated as fluoroapatite. In these sediments total P (P tot) is preserved preferentially over organic C (C org). P regenerated from surficial sediments contributes about 1/3 of the P that is assimilated by benthic microalgae. The phytoplankton P requirement should be entirely supplied from fresh-water sources. These results suggest that oxygen depletion in coastal areas caused by eutrophication enhances P regeneration from sediments, providing the additional P necessary for increased biological productivity. The development of anoxic bottom waters in coastal areas enhances the recycling of P, exacerbating the nutrient requirement in the area. A geochemical record of P burial in a longer sedimentary sequence revealed an increasing trend of P tot and organic P (P org) contents occurring approximately 50 years BP (after 1950), probably due to increasing use of inorganic fertilizers and detergents in the area.

  18. Investigation of model capability in capturing vertical hydrodynamic coastal processes: a case study in the north Adriatic Sea

    NASA Astrophysics Data System (ADS)

    McKiver, W. J.; Sannino, G.; Braga, F.; Bellafiore, D.

    2016-01-01

    In this work we consider a numerical study of hydrodynamics in the coastal zone using two different models, SHYFEM (shallow water hydrodynamic finite element model) and MITgcm (Massachusetts Institute of Technology general circulation model), to assess their capability to capture the main processes. We focus on the north Adriatic Sea during a strong dense water event that occurred at the beginning of 2012. This serves as an interesting test case to examine both the models strengths and weaknesses, while giving an opportunity to understand how these events affect coastal processes, like upwelling and downwelling, and how they interact with estuarine dynamics. Using the models we examine the impact of setup, surface and lateral boundary treatment, resolution and mixing schemes, as well as assessing the importance of nonhydrostatic dynamics in coastal processes. Both models are able to capture the dense water event, though each displays biases in different regions. The models show large differences in the reproduction of surface patterns, identifying the choice of suitable bulk formulas as a central point for the correct simulation of the thermohaline structure of the coastal zone. Moreover, the different approaches in treating lateral freshwater sources affect the vertical coastal stratification. The results indicate the importance of having high horizontal resolution in the coastal zone, specifically in close proximity to river inputs, in order to reproduce the effect of the complex coastal morphology on the hydrodynamics. A lower resolution offshore is acceptable for the reproduction of the dense water event, even if specific vortical structures are missed. Finally, it is found that nonhydrostatic processes are of little importance for the reproduction of dense water formation in the shelf of the north Adriatic Sea.

  19. Loss of large predatory sharks from the Mediterranean Sea.

    PubMed

    Ferretti, Francesco; Myers, Ransom A; Serena, Fabrizio; Lotze, Heike K

    2008-08-01

    Evidence for severe declines in large predatory fishes is increasing around the world. Because of its long history of intense fishing, the Mediterranean Sea offers a unique perspective on fish population declines over historical timescales. We used a diverse set of records dating back to the early 19th and mid 20th century to reconstruct long-term population trends of large predatory sharks in the northwestern Mediterranean Sea. We compiled 9 time series of abundance indices from commercial and recreational fishery landings, scientific surveys, and sighting records. Generalized linear models were used to extract instantaneous rates of change from each data set, and a meta-analysis was conducted to compare population trends. Only 5 of the 20 species we considered had sufficient records for analysis. Hammerhead (Sphyrna spp.), blue (Prionace glauca), mackerel (Isurus oxyrinchus and Lamna nasus), and thresher sharks (Alopias vulpinus) declined between 96 and 99.99% relative to their former abundance. According to World Conservation Union (IUCN) criteria, these species would be considered critically endangered. So far, the lack of quantitative population assessments has impeded shark conservation in the Mediterranean Sea. Our study fills this critical information gap, suggesting that current levels of exploitation put large sharks at risk of extinction in the Mediterranean Sea. Possible ecosystem effects of these losses involve a disruption of top-down control and a release of midlevel consumers. PMID:18544092

  20. Implementation of an aorcm in the mediterranean sea

    NASA Astrophysics Data System (ADS)

    de Zolt, S.; Lionello, P.; Malguzzi, P.

    2003-04-01

    This study describes a dynamical downscaling in the Mediterranean region, carried out using the coupled atmosphere-ocean-wave model MIAO. The MIAO (Model of Interacting Atmosphere and Ocean) model is composed of three modules, BOLAM (limited area atmospheric circulation model), POM (ocean circulation model) and WAM (ocean waves model), that can be coupled to each other. In the Mediterranean region, which is characterized by complex land-sea distribution, steep orography near the coasts, and intense air-sea interactions, the air-sea fluxes show interesting mesoscale features, important for dense water formation processes and Mediterranean cyclogenesis. In order to study the importance of the coupling between atmosphere and ocean, two two-year long simulations have been carried out in both coupled and uncoupled mode. The differences in the Sea Surface Temperature (SST), precipitation and air-sea interface fields (air-sea fluxes, air temperature, significant wave height, etc.) between the two simulations are discussed. It is stressed that the coupled simulation results in a much better reproduction of the SST annual cycle.

  1. A new contribution to the Late Quaternary tephrostratigraphy of the Mediterranean: Aegean Sea core LC21

    NASA Astrophysics Data System (ADS)

    Satow, C.; Tomlinson, E. L.; Grant, K. M.; Albert, P. G.; Smith, V. C.; Manning, C. J.; Ottolini, L.; Wulf, S.; Rohling, E. J.; Lowe, J. J.; Blockley, S. P. E.; Menzies, M. A.

    2015-06-01

    Tephra layers preserved in marine sediments can contribute to the reconstruction of volcanic histories and potentially act as stratigraphic isochrons to link together environmental records. Recent developments in the detection of volcanic ash (tephra) at levels where none is macroscopically visible (so-called 'crypto-tephra') have greatly enhanced the potential of tephrostratigraphy for synchronising environmental and archaeological records by expanding the areas over which tephras are found. In this paper, crypto-tephra extraction techniques allow the recovery of 8 non-visible tephra layers to add to the 9 visible layers in a marine sediment core (LC21) from the SE Aegean Sea to form the longest, single core record of volcanic activity in the Aegean Sea. Using a novel, shard-specific methodology, sources of the tephra shards are identified on the basis of their major and trace element single-shard geochemistry, by comparison with geochemical data from proximal Mediterranean volcanic stratigraphies. The results indicate that the tephra layers are derived from 14 or 15 separate eruptions in the last ca 161 ka BP: 9 from Santorini; 2 or 3 from Kos, Yali, or Nisyros; 2 from the Campanian province; and one from Pantelleria. The attributions of these tephra layers indicate that 1) inter-Plinian eruptions from Santorini may have produced regionally significant tephra deposits, 2) marine tephrostratigraphies can provide unique and invaluable data to eruptive histories for island volcanoes, and 3) tephra from both Pantelleria and Campania may be used to correlate marine records from the Aegean Sea to those from the Tyrrhenian, Adriatic and Ionian Seas.

  2. Dolphin Morbillivirus Epizootic Resurgence, Mediterranean Sea

    PubMed Central

    Raga, Juan-Antonio; Domingo, Mariano; Corteyn, Mandy; Van Bressem, Marie-Françoise; Fernández, Mercedes; Aznar, Francisco-Javier; Barrett, Thomas

    2008-01-01

    In July 2007, >100 striped dolphins, Stenella coeruleoalba, were found dead along the coast of the Spanish Mediterranean. Of 10 dolphins tested, 7 were positive for a virus strain closely related to the dolphin morbillivirus that was isolated during a previous epizootic in 1990. PMID:18325265

  3. Short-term post-mortality predation and scavenging and longer-term recovery after anoxia in the northern Adriatic Sea

    NASA Astrophysics Data System (ADS)

    Blasnig, M.; Riedel, B.; Zuschin, M.; Schiemer, L.; Stachowitsch, M.

    2013-03-01

    In the Mediterranean, the northern Adriatic Sea shows most features known to promote late-summer hypoxia and anoxia. These features, along with anthropogenic eutrophication and marine snow events, have led to repeated benthic mortalities here. The present study was designed to document the post-anoxia macrofauna dynamics. We deployed an underwater instrument to induce small-scale anoxia in situ (total area 0.5 m2). Two time-lapse camera deployments examined short-term scavenging of the moribund and dead organisms (multi-species clumps consisting of sponges and ascidians) over a 3-day period (August 2008: 71.5 h, September 2008: 67.5 h). Longer-term recovery (2 yr) in the same two plots was examined with an independent photo-series. Predators and scavengers arrived in a distinct sequence. The first to arrive were demersal (Gobius niger, Serranus hepatus) and benthopelagic fishes (Diplodus vulgaris, Pagellus erythrinus), followed by hermit crabs (Paguristes eremita, showing a clear day/night rhythm in presence) and gastropods (Hexaplex trunculus). This sequence of arrival is attributed to the relative speeds of the organisms and their densities. The scavengers remained in dense aggregations (e.g. up to 33 P. eremita individuals at one time) as long as the dead organisms were available. The whole sessile fauna was largely removed or consumed within 7 (August plot) and 13 (September plot) days after anoxia. No macroepibenthic recovery took place in the experimental plots one and two years after anoxia. This study underlines the sensitivity of this soft-bottom community and supports calls for reducing additional anthropogenic disturbances such as damaging commercial fishing practices that impede recolonization and threaten benthic community structure and function over the long-term.

  4. River discharges of water and nutrients to the Mediterranean and Black Sea: Major drivers for ecosystem changes during past and future decades?

    NASA Astrophysics Data System (ADS)

    Ludwig, Wolfgang; Dumont, Egon; Meybeck, Michel; Heussner, Serge

    2009-03-01

    than 5% in the Black Sea. Possible ecological impacts of the changing river inputs should therefore be visible only in productive coastal areas, such as the Gulf of Lions, where PPR can reach more than two thirds of PP. Reported ecosystem changes both in the Adriatic Sea and the Black Sea are concomitant with major changes in the reconstructed river inputs. Further work combining modelling and data collection is needed to test whether this may also have been the case for coastal ecosystems at other places in the Mediterranean and Black Sea.

  5. Truth and consequences: the bioinvasion of the Mediterranean Sea.

    PubMed

    Galil, Bella Sarah

    2012-09-01

    Over 660 alien marine multicellular species have been recorded in the Mediterranean Sea, with many establishing viable populations and subsequently dispersing from their points of entry. A brief overview is presented of the current state of knowledge of bioinvasions in the Mediterranean Sea, with particular attention paid to gelatinous invasive species. A database of alien species records was used to characterize their identity, pattern of expansion and native region, and to discuss the relative importance of different taxa and vectors in the various regions of the sea. The temporal and spatial spread of 4 alien scyphozoans and 2 alien ctenophores is outlined. Although thermophilic species constitute the majority of Mediterranean aliens, Erythrean aliens are predominant in the east, with shipping and mariculture being mainly responsible for introductions in the northwest. The propagule pressure driving the Erythrean invasion is powerful in the establishment and spread of alien species in the eastern Mediterranean. The implications of the enlargement of the Suez Canal, reflecting patterns in global trade and economy, are briefly discussed. Finally, as alien species inventories play a pivotal role in informing regional policy and management decisions and identifying resource priorities, the scientific community is called upon to pay particular attention to their accuracy and veracity. PMID:22938526

  6. Sediment reworking rates in deep sediments of the Mediterranean Sea.

    PubMed

    Barsanti, M; Delbono, I; Schirone, A; Langone, L; Miserocchi, S; Salvi, S; Delfanti, R

    2011-07-01

    Different pelagic areas of the Mediterranean Sea have been investigated in order to quantify physical and biological mixing processes in deep sea sediments. Herein, results of eleven sediment cores sampled at different deep areas (> 2000 m) of the Western and Eastern Mediterranean Sea are presented. ²¹⁰Pb(xs) and ¹³⁷Cs vertical profiles, together with ¹⁴C dating, are used to identify the main processes characterising the different areas and, finally, controlling mixing depths (SML) and bioturbation coefficients (D(b)). Radionuclide vertical profiles and inventories indicate that bioturbation processes are the dominant processes responsible for sediment reworking in deep sea environments. Results show significant differences in sediment mixing depths and bioturbation coefficients among areas of the Mediterranean Sea characterised by different trophic regimes. In particular, in the Oran Rise area, where the Almeria-Oran Front induces frequent phytoplankton blooms, we calculate the highest values of sediment mixing layers (13 cm) and bioturbation coefficients (0.187 cm² yr⁻¹), and the highest values of ²¹⁰Pb(xs) and ¹³⁷Cs inventories. Intermediate values of SML and D(b) (~6 cm and ~0.040 cm² yr⁻¹, respectively) characterise the mesothrophic Algero-Balearic basin, while in the Southern Tyrrhenian Sea mixing parameters (SML of 3 cm and D(b) of 0.011 cm² yr⁻¹ are similar to those calculated for the oligotrophic Eastern Mediterranean (SML of 2 cm and D(b) of ~0.005 cm² yr⁻¹). PMID:21561644

  7. High-resolution sea wind hindcasts over the Mediterranean area

    NASA Astrophysics Data System (ADS)

    Menendez, M.; García-Díez, M.; Fita, L.; Fernández, J.; Méndez, F. J.; Gutiérrez, J. M.

    2014-04-01

    The goal of this study is to develop a high-resolution atmospheric hindcast over the Mediterranean area using the WRF-ARW model, focusing on offshore surface wind fields. In order to choose the most adequate model configuration, the study provides details on the calibration of the experimental saet-up through a sensitivity test considering the October-December 2001 period (the 2001 super-storm event in the West Mediterranean). A daily forecast outperforms the spectral technique of previous products and the boundary data from ERA-Interim reanalysis produces the most accurate estimates in terms of wind variability and hour-to-hour correspondence. According to the sensitivity test, two data sets of wind hindcast are produced: the SeaWind I (30-km horizontal resolution for a period of 60 years) and the SeaWind II (15-km horizontal resolution for 20 years). The validation of the resulting surface winds is undertaken considering two offshore observational datasets. On the one hand, hourly surface buoy stations are used to validate wind time series at specific locations; on the other hand, wind altimeter satellite observations are considered for spatial validation in the whole Mediterranean Sea. The results obtained from this validation process show a very good agreement with observations for the southern Europe region. Finally, SeaWind I and II are used to characterize offshore wind fields in the Mediterranean Sea. The statistical structure of sea surface wind is analyzed and the agreement with Weibull probability distribution is discussed. In addition, wind persistence and extreme wind speed (50 year return period) are characterized and relevant areas of wind power generation are described by estimating wind energy quantities.

  8. Modeling land subsidence due to shallow-water hydrocarbon production: A case study in the northern Adriatic Sea

    NASA Astrophysics Data System (ADS)

    Gambolati, G.; Castelletto, N.; Ferronato, M.; Janna, C.; Teatini, P.

    2012-12-01

    One major environmental concern of subsurface fluid withdrawal is land subsidence. The issue of a reliable estimate and prediction of the expected anthropogenic land subsidence is particularly important whenever the production of hydrocarbon (oil and gas) occurs from large reservoirs located close to deltaic zones (e.g., Mississippi, Po, Nile, Niger, Yellow rivers) or shallow-water with low-lying coastlands (e.g., Northern Caspian sea, Dutch Wadden Sea). In such cases even a small reduction of the ground elevation relative to the mean sea level may impact seriously on human settlements and natural environment. The monitoring of the ongoing land subsidence has been significantly improved over the last decade by SAR-based interferometry. These measurements can be quite effectively used to map the process and calibrate geomechanical models for predicting the future event. However, this powerful methodology cannot be implemented off-shore. Although permanent GPS stations can be established to monitor the movement of the production facilities usually installed above the gravity center of a reservoir, an accurate characterization of the settlement bowl affecting the sea bottom, with a possible migration toward the shore, is a challenge still today. In the present communication the case study of the Riccione gas reservoir is discussed. The field is located in the near-shore northern Adriatic Sea, approximately 15 km far from the coastline, where the seawater height is about 20 m. The gas-bearing strata are 1100 m deep and are hydraulically connected to a relatively weak aquifer. Production of 70% of the cumulative reserves as of 2006 yielded a pore pressure decrease of 60 bars. Reliable geometry and geomechanical properties of the depleted formations were detected with the aid of a 3D seismic survey and a borehole equipped with radioactive markers, respectively. The latter pointed out that the Riccione formations are characterized by an unusually high oedometer

  9. The Yellow Gorgonian Eunicella cavolini: Demography and Disturbance Levels across the Mediterranean Sea

    PubMed Central

    Linares, Cristina; Koutsoubas, Drosos; Garrabou, Joaquim

    2015-01-01

    The yellow octocoral Eunicella cavolini is one of the most common gorgonians thriving in Mediterranean hard-bottom communities. However, information regarding its distribution and ecology in several parts of the Mediterranean is lacking, while population trends and conservation status remain largely unknown. We investigated 19 populations of E. cavolini over three representative geographic regions: the NW Mediterranean, CE Adriatic, and N Aegean. Focusing on the upper bathymetric range of the species (<40 m), data were collected on the populations’ upper depth limit, density, colony height, and extent of injury. A three-level hierarchical sampling design was applied to assess the existence of spatial patterns, using: a) regions (located thousands of km apart), b) localities within regions (tens to hundreds of km apart), and c) sites within localities (hundreds of m to a few km apart). In the NW Mediterranean and CE Adriatic, the upper distribution limit was at depths ≤15 m, whereas in the N Aegean most populations were found deeper than 30 m. Population density ranged between 4.46-62 colonies per m2, while mean colony height was 15.6±8.9 SD cm with a maximum of 62 cm. The NW Mediterranean sites were characterized by dense populations dominated by small colonies (<20 cm), periodic recruitment, and low proportion of large gorgonians (>30 cm). The CE Adriatic displayed intermediate densities, with well-structured populations, and continuous recruitment. In the N Aegean, most populations presented low densities, high proportion of large colonies, but low number of small colonies, signifying limited recruitment. Disturbance levels, as a function of extent and type of injury, are discussed in relation to past or present human-induced threats. This work represents geographically the most wide ranging demographic study of a Mediterranean octocoral to date. The quantitative information obtained provides a basis for future monitoring at a Mediterranean scale. PMID

  10. The Yellow Gorgonian Eunicella cavolini: Demography and Disturbance Levels across the Mediterranean Sea.

    PubMed

    Sini, Maria; Kipson, Silvija; Linares, Cristina; Koutsoubas, Drosos; Garrabou, Joaquim

    2015-01-01

    The yellow octocoral Eunicella cavolini is one of the most common gorgonians thriving in Mediterranean hard-bottom communities. However, information regarding its distribution and ecology in several parts of the Mediterranean is lacking, while population trends and conservation status remain largely unknown. We investigated 19 populations of E. cavolini over three representative geographic regions: the NW Mediterranean, CE Adriatic, and N Aegean. Focusing on the upper bathymetric range of the species (<40 m), data were collected on the populations' upper depth limit, density, colony height, and extent of injury. A three-level hierarchical sampling design was applied to assess the existence of spatial patterns, using: a) regions (located thousands of km apart), b) localities within regions (tens to hundreds of km apart), and c) sites within localities (hundreds of m to a few km apart). In the NW Mediterranean and CE Adriatic, the upper distribution limit was at depths ≤15 m, whereas in the N Aegean most populations were found deeper than 30 m. Population density ranged between 4.46-62 colonies per m2, while mean colony height was 15.6±8.9 SD cm with a maximum of 62 cm. The NW Mediterranean sites were characterized by dense populations dominated by small colonies (<20 cm), periodic recruitment, and low proportion of large gorgonians (>30 cm). The CE Adriatic displayed intermediate densities, with well-structured populations, and continuous recruitment. In the N Aegean, most populations presented low densities, high proportion of large colonies, but low number of small colonies, signifying limited recruitment. Disturbance levels, as a function of extent and type of injury, are discussed in relation to past or present human-induced threats. This work represents geographically the most wide ranging demographic study of a Mediterranean octocoral to date. The quantitative information obtained provides a basis for future monitoring at a Mediterranean scale. PMID

  11. Surface drifter derived circulation in the northern and middle Adriatic Sea: Response to wind regime and season

    USGS Publications Warehouse

    Ursella, L.; Poulain, P.-M.; Signell, R.P.

    2007-01-01

    More than 120 satellite-tracked drifters were deployed in the northern and middle Adriatic (NMA) Sea between September 2002 and November 2003, with the purpose of studying the surface circulation at mesoscale to seasonal scale in relation to wind forcing, river runoff, and bottom topography. Pseudo-Eulerian and Lagrangian statistics were calculated from the low-pass-filtered drifter velocity data between September 2002 and December 2003. The structure of the mean circulation is determined with unprecedented high horizontal resolution by the new data. In particular, mean currents, velocity variance, and kinetic energy levels are shown to be maximal in the Western Adriatic Current (WAC). Separating data into seasons, we found that the mean kinetic energy is maximal in fall, with high values also in winter, while it is significantly weaker in summer. High-resolution Local Area Model Italy winds were used to relate the drifter velocities to the wind fields. The surface currents appear to be significantly influenced by the winds. The mean flow during the northeasterly bora regime shows an intensification of the across-basin recirculating currents. In addition, the WAC is strongly intensified both in intensity and in its offshore lateral extension. In the southeasterly sirocco regime, northward flow without recirculation dominates in the eastern half of the basin, while during northwesterly maestro the WAC is enhanced. Separating the data into low and high Po River discharge rates for low-wind conditions shows that the WAC and the velocity fluctuations in front of the Po delta are stronger for high Po River runoff. Lagrangian covariance, diffusivity, and integral time and space scales are larger in the along-basin direction and are maximal in the southern portion of the WAC. Copyright 2006 by the American Geophysical Union.

  12. Relative sea level trend and variability in the central Mediterranean in the time span 1872-2014 from tide gauge data: implications for future projections

    NASA Astrophysics Data System (ADS)

    Anzidei, Marco; Vecchio, Antonio

    2015-04-01

    We used tidal data collected in the time span 1872-2014 from a set of historical and modern stations located in the central Mediterranean, along the coasts of Italy, France, Slovenia and Croatia. The longest records span across the last two or three centuries for the tidal stations of Genova, Marseille, Trieste and Venice. While data from Bakar, Dubrovink, Rovinji and Split, all located along the coast of the Adriatic sea, provide valid records for a time span about 50 years long. In addition to these stations, since 1998 become available for the Italian region new sea level data from the dense national tidal network (www.mareografico.it). These digital stations are collecting data continuously at 10 minute sampling interval with a nominal accuracy at 1 mm. Therefore, in addition to the historical stations, we have the opportunity to analyze a sea level data set that cover about the last 16 years. In this study we show and discuss the results of our analysis of sea level data for the central Mediterranean, providing new insights on sea level trend and variability for about the past 140 years. Finally, based on sea level data and IPCC reports, we provide future sea level projections for this region for the year 2100 with implications for coastal flooding of lowland areas.

  13. Water-gas dynamics and coastal land subsidence over Chioggia Mare field, northern Adriatic Sea

    NASA Astrophysics Data System (ADS)

    Teatini, Pietro; Baú, Domenico; Gambolati, Giuseppe

    2000-09-01

    A major development programme comprising 15 gas fields of the northern Adriatic Sea has recently been submitted to the Ministry of the Environment, VIA Committee for the assessment of the environmental impact, by ENI-Agip, the Italian national oil company. One of the largest reservoirs is Chioggia Mare, located about 10 km offshore of the Venetian littoral, with a burial depth of 1000-1400 m. The planned gas production from this field is expected to impact the shoreline stability with a potential threat to the city of Venice, 25 km northwest of the center of Chioggia Mare. To evaluate the risk of anthropogenic land subsidence due to gas withdrawal, a numerical model was developed that predicts the compaction of both the gas-bearing formations and the lateral/bottom aquifer (water drive) during a 13-year producing and a 12-year post-production period, and the transference of the deep compaction to the ground surface. To address the uncertainty of a few important hydromechanical parameters, several scenarios are simulated and the most pessimistic predictions obtained. The modeling results show that at most 1 cm of land subsidence over 25 years may be expected at the city of Chioggia, whereas Venice is not subject to settlement. If aquifer drawdown is mediated by water injection, land subsidence is arrested 5 km offshore, with the Chioggia littoral zone experiencing a rebound of 0.6-0.7 cm. Résumé. Un important programme de développement portant sur 15 gisements de gaz du nord de l'Adriatique a été récemment soumis au Comité VIA pour l'évaluation de l'impact sur l'environnement du Ministère de l'Environnement, par la société ENI-Agip, la compagnie nationale pétrolière italienne. L'un des plus importants réservoirs est celui de Chioggia Mare, situé à environ 10 km au large du littoral vénitien, à une profondeur de 1000 à 1400 m. La production de gaz prévue pour ce gisement laisse envisager un impact sur la stabilité du trait de côte, avec une

  14. Ultraphytoplankton basin-scale distribution in the eastern Mediterranean Sea in winter: link to hydrodynamism and nutrients

    NASA Astrophysics Data System (ADS)

    Denis, M.; Thyssen, M.; Martin, V.; Manca, B.; Vidussi, F.

    2010-07-01

    The basin-scale distribution of ultraphytoplankton (<10 μm) was determined in the upper 200 m of the eastern Mediterranean Sea during the winter season. Four clusters were resolved by flow cytometry on the basis of their optical properties and identified as Synechococcus, Prochlorococcus, pico- (<3 μm) and nanoeukaryotes (3-10 μm). Synechococcus was the most abundant population (maximum abundance of about 37 000 cells cm-3) and contributed up to 67.7% to the overall ultraphytoplanktonic carbon biomass, whereas the contribution of Prochlorococcus never exceeded 6.5%. The maximum integrated carbon biomass was 1763, 453, 58 and 571 mg C m-2 for nanoeukaryotes, picoeukaryotes, Prochlorococcus and Synechococcus respectively. Water mass properties were analyzed on the basis of temperature and salinity distributions in order to account for the general circulation and locate the main hydrodynamic structures (fronts, gyres, transition between western and eastern basins). The effect of the main hydrodynamic structures and nutrients on the ultraphytoplankton distribution was investigated. No positive correlation between nutrients and phytoplankton could be established when considering large scales. However, below 50 m depth, nutrient ratios between particular stations were correlated to corresponding density ratios. In contrast, significant relationships were found between Synechococcus abundance and density, resulting from the impact of a gyre in southern Adriatic basin and a thermohaline front in the Ionian basin. A significant relationship was also found between picoeukaryotes and salinity in the comparison of western and eastern Mediterranean Sea.

  15. {sup 210}Pb dating of sediments from the central and the northern Adriatic Sea: The deposition and preservation of sedimentary organic carbon

    SciTech Connect

    Hamilton, T.; Fowler, S.; Miquel, J.C.; La Rosa, J.

    1996-04-01

    A central goal of the ELNA project is to assess the carbon assimilation capacity of the Northern Adriatic Sea. This requires fundamental quantitative information on budgets and sinks of organic carbon. Any change in carbon production in the water column should be reflected in the underlying sediments. Moreover, the fraction of particulate organic carbon reaching the sea floor which is subsequently preserved in the sediment will be strongly coupled to sediment accumulation and mixing. In this study a series of box cores were collected in order to characterize a hypothetical eutrophication gradient extending from the Po River outflow region in the north down to the shallow meso-Adriatic depression (Jabuka Pit). The main tasks assigned to IAEA-MEL were to provide {sup 210}Pb derived sedimentation and dry-mass accumulation rates and to examine the possible correlations between sedimentary processes, the deposition and preservation of sedimentary organic carbon and pelagic primary productivity.

  16. Modelling of the anthropogenic tritium transient and its decay product helium-3 in the Mediterranean Sea using a high-resolution regional model

    NASA Astrophysics Data System (ADS)

    Ayache, M.; Dutay, J.-C.; Jean-Baptiste, P.; Beranger, K.; Arsouze, T.; Beuvier, J.; Palmieri, J.; Le-vu, B.; Roether, W.

    2015-05-01

    This numerical study provides the first simulation of the anthropogenic tritium invasion and its decay product helium-3 (3He) in the Mediterranean Sea. The simulation covers the entire tritium (3H) transient generated by the atmospheric nuclear weapons tests performed in the 1950s and early 1960s and is run till 2011. Tritium, helium-3 and their derived age estimates are particularly suitable for studying intermediate and deep-water ventilation and spreading of water masses at intermediate/deep levels. The simulation is made using a high-resolution regional model NEMO (Nucleus for European Modelling of the Ocean), in a regional configuration for the Mediterranean Sea called MED12, forced at the surface with prescribed tritium evolution derived from observations. The simulation is compared to measurements of tritium and helium-3 performed along large-scale transects in the Mediterranean Sea during the last few decades on cruises of R/V Meteor: M5/6, M31/1, M44/4, M51/2, M84/3, and R/V Poseidon: 234. The results show that the input function used for the tritium generates a realistic distribution of the main hydrographic features of the Mediterranean Sea circulation. In the eastern basin, the results highlight the weak formation of Adriatic Deep Water in the model, which explains its weak contribution to the Eastern Mediterranean Deep Water (EMDW) in the Ionian sub-basin. It produces a realistic representation of the Eastern Mediterranean Transient (EMT) signal, simulating a deep-water formation in the Aegean sub-basin at the beginning of 1993, with a realistic timing of deep-water renewal in the eastern basin.

  17. Towards acoustic UHE neutrino detection in the Mediterranean sea

    NASA Astrophysics Data System (ADS)

    Riccobene, G.

    2012-11-01

    Acoustic detection is proposed as a promising detection technique for Extreme High energy neutrinos. This technique is based on the detection of the acoustic signature of neutrino-induced showers in water: a bipolar signal, having a bandwidth of few 10 kHz, with cylindrical wave front. During the last decade, the possibility of access to deep-sea infrastructures developed for Cherenkov telescopes, allowed start-up of intense R&D activities on acoustic detection. In the framework of the activities of ANTARES, NEMO and KM3NeT, several small size experiments were run in order to measure acoustic noise in deep sea and test “neutrino-like” acoustic event detection. These activities have set milestones both for future HE neutrino detectors, for innovative deep-sea technology and for Earth-Sea science. A review on acoustic neutrino detection and projects running in the Mediterranean Sea is presented.

  18. Modeling of the anthropogenic tritium transient, and its decay product Helium-3, in the Mediterranean Sea, using a high-resolution regional model.

    NASA Astrophysics Data System (ADS)

    Ayache, Mohamed; Dutay, Jean-Claude; Jean-Baptiste, Philippe; Beranger, Karine; Arsouze, Thomas; Beuvier, Jonathan; Palmieri, Julien; Le-Vu, Briac; Roether, Wolfgang

    2014-05-01

    This numerical study provides, for the first time in the Mediterranean Sea, a simulation of the anthropogenic tritium invasion and its decay product helium-3. The simulation is starting in 1950 and go up to 2011. It thus covers a 60-year period spanning the entire tritium transient generated by the atmospheric nuclear-weapon tests performed in the 1950s and early 1960s. The tritium is known as a passive tracer, which allows a good representation/signature of the upper water stratification, as well as, the high mixing in convection areas and the spreading at intermediate/deep levels. The tracer simulation is done using a high resolution regional model NEMO-MED12 (Beuvier et al., JGR, 2012) with at surface prescribed tritium concentration according to the temporal evolution derived from observations (see Roether et al., OS, 2013). Several measurement of tritium and helium-3 performed along large scale transects in the Mediterranean Sea during the last decades allow a comparison of the simulated results with numerous in situ sections from cruises of Meteor M5/6, M31/1, M44/4, M51/2, M84/3, and Poseidon 234. The results show that the parameterization used for the tritium boundary conditions generates realistic results. Besides we calculate the tracer-age distributions according to the relationship between tritium and its radioactive decay product helium-3. In the eastern basin, the tracer simulation results highlight the weak formation of Adriatic Deep Water (ADW) in the Adriatic Sea followed by a week contribution to the Eastern Mediterranean Deep Water (EMDW) in the Ionian sub-basin while it shows a good representation of the Eastern Mediterranean Transient (EMT) signal from the Aegean Sea followed by a great contribution to the EMDW. In the western basin, the particularly intense deep convection event of winter 2005 in the Gulf of Lions during the Western Mediterranean Transition (WMT) is well simulated. However the spreading of the recently ventilated deep water to

  19. Historical pattern and mass balance of trace metals in sediments of the northwestern Adriatic Sea Shelf.

    PubMed

    Romano, Stefania; Langone, Leonardo; Frignani, Mauro; Albertazzi, Sonia; Focaccia, Paola; Bellucci, Luca Giorgio; Ravaioli, Mariangela

    2013-11-15

    In view of the recent action in Marine Strategy Framework Directive, reconstructing the history of anthropogenic metal inputs and calculating the budgets for the northwestern part of the Italian Adriatic basin can provide a benchmark for comparison with new evidences and enlighten recent environmental changes. Among the metals, the attention was focused on Pb and Zn, as they provide the most significant anthropogenic signals. In 1988, areal distributions clearly identified the Po, Adige and Brenta rivers as the main sources of contaminants. The study area was divided in three compartments. The area in front of the Po delta represented a sink for metals but the accumulation of Zn and Pb integrated over the entire study area suggests an effective export throughout southern boundary. Most concentration-depth/year profiles in cores showed an upward increase from the Italian Unification (1861), with a still significant anthropogenic supply at the time of sampling. PMID:24119313

  20. From seasonal to decadal inter-annual variability of mesozooplankton biomass in the Northern Adriatic Sea (Gulf of Trieste)

    NASA Astrophysics Data System (ADS)

    Kamburska, Lyudmila; Fonda-Umani, Serena

    2009-11-01

    This paper reports the rate of change of mesozooplankton biomass on seasonal, inter-annual and decadal time scale in the Gulf of Trieste (NE Mediterranean, Northern Adriatic). We measured variability in mesozooplankton dry weight (mg DW m - 3 ), organic carbon and nitrogen contents of the DW in relation to mesozooplankton taxonomic structure and some environmental parameters. The study is based on data obtained from mesozooplankton samples collected monthly by a vertical WP2 net (200 µm) from January 1986 to September 2005 at one monitoring station, a coastal site in the Gulf of Trieste. We considered mesozooplankton DW in relation to copepods, phytoplankton taxonomic structure, water temperature and North Atlantic Oscillation. For further analyses we counted also on data for DW for the period 1972-1980, monthly data for organic carbon (mg C m - 3 ) and nitrogen contents (mg N m - 3 ) of the DW for the period 1991-2005, determined by a CHN Elemental Analyzer. We explored statistically our high temporal resolution time series data picking out the main features: seasonal components and trends. Mesozooplankton DW ranged from only 1 mg m - 3 (January 1977) to 95 mg m - 3 (March 1990) in the coastal ecosystem of the Northern Adriatic during the period 1972-2005. The annual cycle of the DW was found to be bimodal with maximum in late winter-spring and a weaker one in late summer. Maximum DW were regularly recorded when Copepods prevailed the mesozooplankton community structure. Similarly, high organic carbon and nitrogen contents were detected when copepods dominated, although wide-ranging on a seasonal scale. Irregular intra- and inter-annual fluctuations were typical mostly during the 1990s. Mesozooplankton DW sharply shifted since 2001-2002 to the level exceeding the observed one during the regime of the 1980s. Our results indicate substantial changes in the seasonal timing of mesozooplankton DW, which together with decadal inter-annual fluctuations match

  1. Concentration of selected trace elements and PCBs in sediments from the Adriatic Sea

    SciTech Connect

    Fowler, S W; Hamilton, T F; Coquery, M; Villeneuve, J-P; Horvat, M

    2000-07-26

    A broad baseline study of the levels and distributions of trace metals and PCB compounds in sediments has been undertaken. PCB concentrations in surface sediments reflect the source of these contaminates in the region. The highest PCB concentrations as Aroclor 1260 (approximately 10 ng g{sup -1}) were found in sediments near the outflow of the Po river. The lowest concentrations (1.5 ng g{sup -1} dry) were associated with the sediments from the Jabuka Pit in the Middle Adriatic. These values are quite similar to total PCBs (<1.0-17) measured in surface sediments sampled off the coast of Croatia in 1977-78. Thus, based on the limited amount of new data available, it appears that there has been little, if any, decrease in PCB loading in Adriatic sediments over the past 15 years. Downcore profiles of PCBs in sediment cores are also discussed from a pollution history standpoint. Likewise, total mercury in surface sediments was also highest at stations off the Po (403-499 ng g{sup -1} dry) and lowest (67-224 ng g{sup -1}) in the Jabuka Pit. In one core located just south of the Po outflow, total Hg concentrations at all depths were relatively high decreasing gradually from approximately 400 ng g{sup -1} in the top 4 cm to roughly 200 ng g{sup -1} at a depth of 32 cm. Using a {sup 210}Pb-derived sedimentation rate of 0.26 em Y{sup -1} for this station, it appears that anthropogenic inputs of mercury may have been responsible for the gradual increase in total mercury noted over the last 125 years.

  2. Spatial variations of particle scavenging rates within the central and northern Adriatic Sea: use of U--Th disequilibria

    SciTech Connect

    Hamilton, T. F., LLNL

    1998-04-01

    Dissolved and particlulate Thorium-234 ({sup 234}Th) were measured in near surface waters from the Central and Northern Adriatic Sea in order to gain an insight into the intensity and variability of active scavenging and particle removal processes. Dissolved {sup 234}Th to Uranium-238 ({sup 238}U) activity ratios vary from 0.21 to 0.75 and clearly imply that {sup 234}Th is being actively scavenged from sea water on a timescale of <3 months. The scavenging rate of dissolved {sup 234}Th with respect to scavenging onto particles appears to correlate with primary productivity measurements. Scavenging and rapid removal of particulate {sup 234}Th from the water column is best explained by a mechanism of zooplankton grazing and fecal pellet production. At one sight in the Jabuka Pit, particulate {sup 234}Th residence times below the pycnocline are long (30-40 days) suggesting that particles are being more readily recycled at these depths. By comparison, in a seawater profile collected near the Po outflow region, {sup 234}Th is depleted with respect to {sup 238}U through the entire water column. We conclude from this assessment that particles in waters near the Po River outflow will be more efficiently transported to bottom sediments compared with those in deeper waters over the Jabuka Pit.

  3. Fin whales and microplastics: The Mediterranean Sea and the Sea of Cortez scenarios.

    PubMed

    Fossi, Maria Cristina; Marsili, Letizia; Baini, Matteo; Giannetti, Matteo; Coppola, Daniele; Guerranti, Cristiana; Caliani, Ilaria; Minutoli, Roberta; Lauriano, Giancarlo; Finoia, Maria Grazia; Rubegni, Fabrizio; Panigada, Simone; Bérubé, Martine; Urbán Ramírez, Jorge; Panti, Cristina

    2016-02-01

    The impact that microplastics have on baleen whales is a question that remains largely unexplored. This study examined the interaction between free-ranging fin whales (Balaenoptera physalus) and microplastics by comparing populations living in two semi-enclosed basins, the Mediterranean Sea and the Sea of Cortez (Gulf of California, Mexico). The results indicate that a considerable abundance of microplastics and plastic additives exists in the neustonic samples from Pelagos Sanctuary of the Mediterranean Sea, and that pelagic areas containing high densities of microplastics overlap with whale feeding grounds, suggesting that whales are exposed to microplastics during foraging; this was confirmed by the observation of a temporal increase in toxicological stress in whales. Given the abundance of microplastics in the Mediterranean environment, along with the high concentrations of Persistent Bioaccumulative and Toxic (PBT) chemicals, plastic additives and biomarker responses detected in the biopsies of Mediterranean whales as compared to those in whales inhabiting the Sea of Cortez, we believe that exposure to microplastics because of direct ingestion and consumption of contaminated prey poses a major threat to the health of fin whales in the Mediterranean Sea. PMID:26637933

  4. The surface circulation in the eastern basin of the Mediterranean Sea

    NASA Astrophysics Data System (ADS)

    Hamad, N.; Millot, C.; Taupier-Letage, I.

    2003-04-01

    The POEM-schema of the Atlantic Water (AW, http://ciesm.org/events/RT5-WaterMassAcronyms.pdf) circulation in the eastern basin of the Mediterranean Sea widely referred to nowadays (Robinson et al., 1991, completed by Robinson and Golnaraghi, 1993, and by Malanotte-Rizzoli et al., 1997) represents, in particular, a jet meandering offshore across the whole basin. No information is given on the southern part of the basin and no mention is made of a possible overall alongslope anticlockwise flow there, as suggested by a contemporaneous analysis of infrared satellite images (Le Vourch et al., 1992; Millot, 1992). A roughly similar controversy was elucidated in the western basin where such imagery was proven reliable. This has motivated the detailed analysis of daily and weekly composite images (about 1000) during the period 1996-2000, and of monthly composites available since 1985. Our analysis shows that AW circulates alongslope and anticlockwise around the whole basin, as indicated by Nielsen (1912) who considered the Coriolis effect as dominant. This circulation, which is permanent from Tunisia to Turkey, exists more or less temporarily in the Aegean, in the Ionian around Greece and in the Adriatic, due to the Etesians. However, a branch having spread for years (up to early 1998) from the channel of Sicily towards the northern Ionian before vanishing represents marked interannual (not seasonal) variability. Being unstable during most of its circuit, the AW flow generates mesoscale eddies which had not been correctly described before and which represent a relatively large amount of AW. Other eddies are known to be generated by orographic effects on the wind field, especially the Etesians. Both kinds of eddies play a fundamental role in spreading AW from alongslope towards the open basin. Although these eddies have characteristics almost specific to each subbasin and/or generation mechanism, the largest ones are anticyclonic, both kinds reach diameters of a few 100s km

  5. Water-gas dynamics and coastal land subsidence over Chioggia Mare field, northern Adriatic Sea

    NASA Astrophysics Data System (ADS)

    Teatini, Pietro; Baú, Domenico; Gambolati, Giuseppe

    2000-09-01

    A major development programme comprising 15 gas fields of the northern Adriatic Sea has recently been submitted to the Ministry of the Environment, VIA Committee for the assessment of the environmental impact, by ENI-Agip, the Italian national oil company. One of the largest reservoirs is Chioggia Mare, located about 10 km offshore of the Venetian littoral, with a burial depth of 1000-1400 m. The planned gas production from this field is expected to impact the shoreline stability with a potential threat to the city of Venice, 25 km northwest of the center of Chioggia Mare. To evaluate the risk of anthropogenic land subsidence due to gas withdrawal, a numerical model was developed that predicts the compaction of both the gas-bearing formations and the lateral/bottom aquifer (water drive) during a 13-year producing and a 12-year post-production period, and the transference of the deep compaction to the ground surface. To address the uncertainty of a few important hydromechanical parameters, several scenarios are simulated and the most pessimistic predictions obtained. The modeling results show that at most 1 cm of land subsidence over 25 years may be expected at the city of Chioggia, whereas Venice is not subject to settlement. If aquifer drawdown is mediated by water injection, land subsidence is arrested 5 km offshore, with the Chioggia littoral zone experiencing a rebound of 0.6-0.7 cm. Résumé. Un important programme de développement portant sur 15 gisements de gaz du nord de l'Adriatique a été récemment soumis au Comité VIA pour l'évaluation de l'impact sur l'environnement du Ministère de l'Environnement, par la société ENI-Agip, la compagnie nationale pétrolière italienne. L'un des plus importants réservoirs est celui de Chioggia Mare, situé à environ 10 km au large du littoral vénitien, à une profondeur de 1000 à 1400 m. La production de gaz prévue pour ce gisement laisse envisager un impact sur la stabilité du trait de côte, avec une

  6. Vortices generation mechanisms in North western Mediterranean Sea

    NASA Astrophysics Data System (ADS)

    Fraunie, P.; Redondo, J. M.; Schaeffer, A.; Molcard, A.; Forget, P.; Garreau, P.

    2012-04-01

    Mesoscale eddies have been observed in Northwestern Mediterranean Sea from satellites, RV cruises and more recently using HF radars. Different non linear mechanisms have been identified and investigated using process oriented high resolution numerical modelling. In particular, wind induced inertial motion and baroclinic instability cases have been illustrated and documented. Statistics of vortices occurence allow a better accounting for coherent structures for pollutants and nutriments dispersion and retention. Acknowledgements : GIRAC project (FUI - CG83 -TPM), ESA, HYMEX programme

  7. Per- and polyfluoroalkyl substances in the Western Mediterranean Sea waters.

    PubMed

    Brumovský, Miroslav; Karásková, Pavlína; Borghini, Mireno; Nizzetto, Luca

    2016-09-01

    The spatial and temporal distribution of per- and polyfluoroalkyl substances (PFASs) in the open Western Mediterranean Sea waters was investigated in this study for the first time. In addition to surface water samples, a deep water sample (1390 m depth) collected in the center of the western basin was analyzed. Perfluorohexanoic acid (PFHxA), perfluoroheptanoic acid (PFHpA), perfluorooctanoic acid (PFOA), perfluorohexanesulfonate (PFHxS) and perfluorooctanesulfonate (PFOS) were detected in all samples and were the dominant PFASs found. The sum of PFAS concentrations (ΣPFASs) ranged 246-515 pg/L for surface water samples. PFASs in surface water had a relatively homogeneous distribution with levels similar to those previously measured in the Atlantic near the Strait of Gibraltar, in water masses feeding the inflow to the Mediterranean Sea. Higher concentrations of PFHxA, PFHpA and PFHxS were, however, found in the present study. Inflowing Atlantic water and river/coastal discharges are likely the major sources of PFASs to the Western Mediterranean basin. Slightly lower (factor of 2) ΣPFASs was found in the deep water sample (141 pg/L). Such a relatively high contamination of deep water is likely to be linked to recurring deep water renewal fed by downwelling events in the Gulf of Lion and/or Ligurian Sea. PMID:27314632

  8. Sediment transport processes from the topset to the foreset of a crenulated clinoform (Adriatic Sea)

    NASA Astrophysics Data System (ADS)

    Puig, P.; Ogston, A. S.; Guillén, J.; Fain, A. M. V.; Palanques, A.

    2007-02-01

    Crenulated clinoforms of complex and uncertain origin characterize large portions of the Late-Holocene prograding mud wedge in the western Adriatic continental shelf. Sediment failure was originally postulated as the most plausible mechanism for the formation of the crenulations. Subsequent work has shown that, although the origin of the crenulations may have been related to deformation processes, their maintenance through time seems to be better explained by different sediment accumulation rates in the flat and steep flanks. In order to establish relationships between active sediment dynamics, across-shelf transport and sediment accumulation in these crenulated clinoforms, two tripods and a mooring were deployed off the Pescara River during autumn and winter 2002-2003 as part of the EuroSTRATAFORM program, and in combination with the Po and Apennine Sediment Transport and Accumulation (PASTA) study. The tripods were placed on the shallow topset region and close to the clinoform roll-over point (i.e., offlap break), at 12 and 20-m water depth, respectively, and the mooring was located at 50-m depth, in the crenulated foreset region. Several sediment-resuspension events were recorded, mainly related to Bora and Sirocco storms, during which wave-orbital and current velocities increased considerably. Sediment transport in the topset region was predominantly towards the SE, following the direction of the coastal current and the bathymetry, but showing a significant offshore component at the roll-over point that was intensified during storm events. Currents at the foreset region were also directed to the SE. In mid-waters they were clearly aligned with the local bathymetry, whereas near the bottom they had an important and persistent offshore component. This current behavior seems to be associated with an intense bottom Ekman transport that causes the near-bottom current to be deflected to the left (i.e., offshore) with respect to the direction of the surface current

  9. Contribution of climate forcing to sea level variations in the Mediterranean Sea

    NASA Astrophysics Data System (ADS)

    Natsiopoulos, Dimitrios A.; Vergos, Georgios S.; Tziavos, Ilias N.

    2016-04-01

    With the availability of an abundance of earth observation data from satellite altimetry missions as well as those from the ENVISAT and CRYOSAT-2 satellites, monitoring of the sea level variations is gaining increased importance. In this work, altimetric data sets from the satellite remote sensing missions of ENVISAT and CRYOSAT-2 have been used to study the variations of the Mediterranean sea level. Alongside, a correlation analysis of Sea Level Anomalies (SLAs) with global and regional climatic indexes that influence the ocean state, has been carried out as well. The raw data used were SLAs from the respective altimetric missions, acquired by the on-board altimeters from the ENVISAT satellite for seven consecutive years (2003-2009) and from the CRYOSAT-2 satellite for six consecutive years (2010-2015). Three oscillation indexes have been investigated, as representative of climate-change and seasonal forcing on the sea level. The first one was the well-known Southern Oscillation Index (SOI), the next one the North Atlantic Oscillation (NAO) index and the third, being primarily more representative of the Mediterranean sea state, was the Mediterranean Oscillation Index (MOI). The possible correlation is investigated in both monthly and annual scales, while a regional multiple regression and a principal component analysis (PCA) between the SLAs and oscillation indexes is carried out. Multiple regression and PCA have been used as tools in order to deduce possible correlations between the Mediterranean sea level variations and the aforementioned oscillation indexes, under the assumption that SLA variations are driven by steric forcing. Finally, evidence of the sea level cyclo-stationarity in the Mediterranean Sea is deduced from the analysis of empirically derived covariance functions at monthly intervals from the available SLA data.

  10. Modelling of the anthropogenic tritium transient and its decay product helium-3 in the Mediterranean Sea using a high-resolution regional model

    NASA Astrophysics Data System (ADS)

    Ayache, M.; Dutay, J.-C.; Jean-Baptiste, P.; Beranger, K.; Arsouze, T.; Beuvier, J.; Palmieri, J.; Le-vu, B.; Roether, W.

    2014-12-01

    This numerical study provides the first simulation of the anthropogenic tritium invasion and its decay product helium-3 (3He) in the Mediterranean Sea. The simulation covers the entire tritium (3H) transient generated by the atmospheric nuclear-weapon tests performed in the 1950s and early 1960s and run till 2011. Tritium, helium-3 and their derived age estimates are particularly suitable for studying intermediate and deep-water ventilation and spreading of water masses at intermediate/deep levels. The simulation is made using a high resolution regional model NEMO-MED12 forced at the surface with prescribed tritium evolution derived from observations. The simulation is compared to measurements of tritium and helium-3 performed along large-scale transects in the Mediterranean Sea during the last few decades on cruises of Meteor M5/6, M31/1, M44/4, M51/2, M84/3, and Poseidon 234. The results show that the input function used for the tritium, generates a realistic distribution of the main hydrographic features of the Mediterranean Sea circulation. In the eastern basin, the results highlight the weak formation of Adriatic Deep Water in the model, which explains its weak contribution to the Eastern Mediterranean Deep Water in the Ionian sub-basin. It produces a realistic representation of the Eastern Mediterranean Transient signal, simulating a deep-water formation in the Aegean sub-basin at the beginning of the 1993, with a realistic timing of deep-water renewal in the eastern basin. In the western basin, the unusual intense deep convection event of winter 2005 in the Gulf of Lions during the Western Mediterranean Transition is simulated. However the spreading of the recently ventilated deep water toward the South is too weak. The ventilation and spreading of the Levantine Intermediate Water from the eastern basin toward the western basin is simulated with realistic tracer-age distribution compared to observation-based estimates.

  11. A checklist of the deep sea fishes of the Levant Sea, Mediterranean Sea.

    PubMed

    Goren, Menachem; Galil, Bella S

    2015-01-01

    We list sixty five fish species collected at depths greater than 500 m in the Levant Basin, including 10 depth records. The Levantine bathyal ichthyofauna is characterized by its eurybathy, with an upper bathymetric boundary that permitted penetration of the shallow Gibraltar and Siculo-Tunisian sills, and a much lower bathymetric boundary than recorded for conspecifics elsewhere. The opportunistic and resilient ichthyofauna re-colonized recently the deep-sea following the last anoxic event (~ 6 kyr), forming assemblages notably distinct from those in the western Mediterranean. The exploration and production of deep seabed hydrocarbons have raised the specter of severe direct impacts to the deep habitats. There is an urgent need for documenting the full extent of deep-sea biodiversity, and for providing information for the development of competent and pragmatic management plans and effective conservation policies. PMID:26250288

  12. First assessment of effects of air-gun seismic shooting on marine resources in the central Adriatic sea

    SciTech Connect

    La Bella, G.; Cannata, S.; Froglia, C.

    1996-11-01

    A series of investigations were carried out to test the effects of air-gun seismic shooting on main fishery resources of the Adriatic Sea during summer 1995. The energy source used for the trial was formed by one air-gun array made up by two sub-arrays consisting in 8 air-guns each developing a total volume of c.a. 2500 i{sup 3} at 2000 psi with an amplitude of 60 bar/m. The interval between two was of 25 s. The intensity was of 210 dB re 1 mPa-m/Hz. Acoustical and spectral analysis were performed simultaneously in the surveyed areas to correlate fishery and behavior observations with sound pattern of the energization. Main results were: (1) Analysis of trawl catch data evidenced no significant changes before and after the air-gun seismic profiling. (2) Echosurvey relative estimate of pelagic biomass, performed simultaneously to trawling operations, failed to evidence any significant change in the pelagic biomass subsequent to the seismic shooting. (3) Small differences were observed in the trammel net catch composition, but one single set of pre-post fishing operations could be done in the study period. (4) Similar density estimate were obtained from dredge surveys performed by an hydraulic dredger before and after air-gun seismic profiling over a clam bed in 14 in depth. (5) Video recording of captive fish, kept into cages moored on the sea bottom at 12 in depth, evidenced a Behavioral response to the approach of the sound source; but no lethal event was recorded on captive sea-bass immediately after the seismic shooting. (6) Biochemical and histological analysis were performed to verify if it is to be related to the captive condition or is somewhat consequent to the air-gun energization. These results confirm that no relevant effects are induced on fishery resources by seismic air-gun shooting.

  13. Assessment of Eutrophication Quality in Greek Coastal Ecosystem (Eastern Mediterranean Sea)

    NASA Astrophysics Data System (ADS)

    Pavlidou, Alexandra; Rousselaki, Eleni; Assimakopoulou, Georgia; Tsapakis, Manolis; Simboura, Nomiki

    2014-05-01

    The Mediterranean Sea has always been considered as one of the most oligotrophic areas in the world, especially in the Eastern part of the Sea. However, eutrophication problems occur in some coastal areas of the Mediterranean (e.g. eastern coasts of Spain, Gulf of Lions, northern Adriatic Sea, Apulian coasts, Saronikos Gulf, Thessaloniki Bay, northern coasts of Greece, etc.). This work is focused on the assessment of the Eutrophication Quality in different coastal areas of Greece affected by various anthropogenic and natural pressures and was performed under the Water Framework Directive. A network of 28 sampling stations was used during two relevant sampling periods, April - May 2012 and March - April 2013, in the framework of the National Monitoring Project of Greece. The Eutrophication assessment method integrates chemical and biological parameters of the water column. A synthetic Eutrophication Index (E.I.) was produced for the greek coastal areas by Primpas et al. quality classification scheme, combining the concentrations of nutrients (phosphate, nitrate, nitrite, ammonia) and chlorophyll-α biomass into a single formula. The E.I. assesses the eutrophication status using a five scale scheme according to the requirements of WFD: (High) less than 0.04; (Good) 0.04-0.38; (moderate) 0.38-0.85; (poor) 0.85-1.51; (bad) >1.51. Nutrient and chlorophyll-a concentrations revealed significant spatial variation among the various coastal areas of Greece influenced by different point and/or diffuse anthropogenic pressures (related to nutrient enrichment), reflecting the level of human-induced impairment where an increase in nutrient loads leads to increased water quality problems. The assessment of E.I showed that during 2012, 32% of the selected coastal areas were characterized as Good, 54% as Moderate and 14% of the selected greek coastal areas were characterized as Poor. During 2012, none of the study areas corresponded to High or Bad eutrophication status. During 2013

  14. Italy - Adriatic Sea - Barbara - A giant gas field marked by seismic velocity anomaly - A subtle trap

    SciTech Connect

    Ianniello, A.; Bolelli, W.; Di Scala, L. )

    1990-09-01

    Barbara gas field, discovered in 1971, is located in the northern sector of the Adriatic offshore. The field is a gentle anticline involving Quaternary clastic sediments and shaped by carbonate Mesozoic morphology. The presence of shallow gas pockets at the crest of the structure distort the seismic signal to such an extent that structural reconstruction using seismic data is not possible. Moreover, time delays and ray-path anomalies do not allow the use of staking velocities for the depth conversion. Seismic attribute analysis, instead of velocities, and time delays on the isochrone maps are providing a key to the understanding of seismic anomalies and are an indirect tool for reconstructing the real structural configuration of the field. The appraisal story of the field illustrates how the previously mentioned complications influenced its delineation and how an understanding of these complications helped in upgrading the reserves from an initial value of 10 billion ECM of gas to 40 billion ECM. Additional data acquired with the development wells tend to increase the estimate. Therefore, Barbara field is the most important Italian gas field of the decade. The producing formation is composed of very thin-bedded sandstone and shale intercalations, representing the peculiarity of this reservoir. Development of the field is being achieved with six production platforms and 72 wells.

  15. Climate change impacts on marine water quality: The case study of the Northern Adriatic sea.

    PubMed

    Rizzi, J; Torresan, S; Critto, A; Zabeo, A; Brigolin, D; Carniel, S; Pastres, R; Marcomini, A

    2016-01-30

    Climate change is posing additional pressures on coastal ecosystems due to variations in water biogeochemical and physico-chemical parameters (e.g., pH, salinity) leading to aquatic ecosystem degradation. With the main aim of analyzing the potential impacts of climate change on marine water quality, a Regional Risk Assessment methodology was developed and applied to coastal marine waters of the North Adriatic. It integrates the outputs of regional biogeochemical and physico-chemical models considering future climate change scenarios (i.e., years 2070 and 2100) with site-specific environmental and socio-economic indicators. Results showed that salinity and temperature will be the main drivers of changes, together with macronutrients, especially in the area of the Po' river delta. The final outputs are exposure, susceptibility and risk maps supporting the communication of the potential consequences of climate change on water quality to decision makers and stakeholders and provide a basis for the definition of adaptation and management strategies. PMID:26152856

  16. Long-period sea-level variations in the Mediterranean

    NASA Astrophysics Data System (ADS)

    Zerbini, Susanna; Raicich, Fabio; Bruni, Sara; del Conte, Sara; Errico, Maddalena; Prati, Claudio; Santi, Efisio

    2016-04-01

    Since the beginning of its long-lasting lifetime, the Wegener initiative has devoted careful consideration to studying sea-level variations/changes across the Mediterranean Sea. Our study focuses on several long-period sea-level time series (from end of 1800 to 2012) acquired in the Mediterranean by tide gauge stations. In general, the analysis and interpretation of these data sets can provide an important contribution to research on climate change and its impacts. We have analyzed the centennial sea-level time series of six fairly well documented tide gauges. They are: Marseille, in France, Alicante in Spain, Genoa, Trieste, Venice and Marina di Ravenna (formerly Porto Corsini), in Italy. The data of the Italian stations of Marina di Ravenna and Venice clearly indicate that land subsidence is responsible for most of the observed rate of relative sea level rise. It is well known that, in the two areas, subsidence is caused by both natural processes and human activities. For these two stations, using levelling data of benchmarks at, and/or close to, the tide gauges, and for the recent years, also GPS and InSAR height time series, modelling of the long-period non-linear behavior of subsidence was successfully accomplished. After removing the land vertical motions, the estimate of the linear long-period sea-level rise at all six stations yielded remarkably consistent values, between +1,2 and +1,3 mm/yr, with associated errors ranging from ±0,2 to ±0,3 mm/yr (95% confidence interval), which also account for the statistical autocorrelation of the time series. These trends in the Mediterranean area are lower than the global mean rate of 1,7±0,2 mm/yr (1901-2010) presented by the IPCC in its 5th Assessment Report; however, they are in full agreement with a global mean sea-level rise estimate, over the period 1901-1990, recently published by Hay et al. (2015, doi:10.1038/nature14093) and obtained using probabilistic techniques that combine sea-level records with physics

  17. A long and winding road: Skeletonema sp transport by Northern Adriatic Dense Waters to the Southern Adriatic Pit.

    NASA Astrophysics Data System (ADS)

    Marcello Falcieri, Francesco; Bernardy Aubry, Fabrizio; Barbariol, Francesco; Benetazzo, Alvise; Bergamasco, Andrea; Boldrin, Alfredo; Bonaldo, Davide; Carniel, Sandro; Finotto, Stefania; Sclavo, Mauro

    2015-04-01

    The semi enclosed Adriatic Sea is a sub basin of the Mediterranean Sea located in its northeastern part; it has a shallow northern part (average depth of 40 m) and a deep Southern Adriatic Pit (SAP) that reaches 1200m. The presence of a wide continental shelf exposed to strong heat and momentum fluxes during winter months makes the Northern Adriatic a formation site of dense waters, generally referred to as Northern Adriatic Dense Water (NAdDW). Once produced, it moves south as a quasi-geostrophically adjusted vein , flowing along the Italian coast and enters the SAP giving origin to descent and cascading dense shelf water bringing into the deep layers oxygen, nutrients and organic compound. In February 2012 a long and intense cold air outbreak, with strong Bora winds, interested the northern part of the Adriatic sea causing a drop in water temperature to less than 6 °C and an increase in density to values as high as 1030.2 kg/m3 (likely the maximum values since 1929). This resulted in a massive production of NAdDW. In order to study the behavior of the NAdDW vein, a rapid response 2 legs cruise (ODW2012) was organized in the southern Adriatic. During the cruise, along with physical and chemical measurements, water and phytoplankton samples were collected at different depths. Usual abundance and distribution with a general decrease in phytoplankton abundance from the surface to the bottom were found in all stations with one exception. The bottom sample of a station located roughly 40 km at 120 m depth in front of Gargano showed a significantly high dominance (40%) of the small diatom Skeletonema sp whose flowering is typical in the surface waters of the northern Adriatic in late winter. The physical parameters of the water column showed signs of the passage of the dense water vein (lower temperature and higher dissolved oxygen concentrations) hence it was hypothesized that those diatoms were actively transported by the NAdDW near-bottom stream. A further

  18. Study of the impact of cyclogenesis at the Mediterranean Sea

    NASA Astrophysics Data System (ADS)

    Ribo, M.; Llasat, C.

    2009-09-01

    The Mediterranean Basin is usually affected by high impact weather events, generating high impacts in all Mediterranean countries and causing important damages. This basin is surrounded by mountains and arid regions, and the interaction of the air flow with the orography barriers produces many effects, the most important is the formation of low pressure centers. This is one of the reasons why the Mediterranean Sea is considered to be the most cyclogenetic area in the world (Jansà, 1997). Floods are also one of the most important natural hazards in the Mediterranean Basin. Flood events occur when soil absorption, runoff or drainage cannot adequately disperse intense rainfall from quasi-stationary or stationary weather systems in short time periods. In some occasions these floods produce high social impact in the affected areas. Our work presents the study of the relationship between the flood episodes and the presence of cyclones in the Mediterranean Basin during those episodes, between 1990 and 2004. Information about social impact of each event has also been considered. To do these analyses the MEDEX database (MEDiterranean EXperiment on cyclones that produce high impact weather in the Mediterranean) has been improved in the frame work of the European FLASH project, and information about cyclones and rainfall has been extracted from the MEDEX cyclones database. A total of 217 flood events had been identified. Once the presence of one or more cyclones during each flood episode has been identified, temporal and regional analyses were made to determine the distribution of the cyclonic centers and to study the evolution of the events. Mediterranean cyclogenesis is leaded by influence of external systems (along the African coast, from the Atlantic Ocean, and from the west of Europe), although the majority of the cyclones (87% of the studied cases) are generated in the Mediterranean Basin, under influence of preexistent systems. There are different Mediterranean

  19. Large-scale spatio-temporal monitoring highlights hotspots of demersal fish diversity in the Mediterranean Sea

    NASA Astrophysics Data System (ADS)

    Granger, Victoria; Fromentin, Jean-Marc; Bez, Nicolas; Relini, Giulio; Meynard, Christine N.; Gaertner, Jean-Claude; Maiorano, Porzia; Garcia Ruiz, Cristina; Follesa, Cristina; Gristina, Michele; Peristeraki, Panagiota; Brind'Amour, Anik; Carbonara, Pierluigi; Charilaou, Charis; Esteban, Antonio; Jadaud, Angélique; Joksimovic, Aleksandar; Kallianiotis, Argyris; Kolitari, Jerina; Manfredi, Chiara; Massuti, Enric; Mifsud, Roberta; Quetglas, Antoni; Refes, Wahid; Sbrana, Mario; Vrgoc, Nedo; Spedicato, Maria Teresa; Mérigot, Bastien

    2015-01-01

    Increasing human pressures and global environmental change may severely affect the diversity of species assemblages and associated ecosystem services. Despite the recent interest in phylogenetic and functional diversity, our knowledge on large spatio-temporal patterns of demersal fish diversity sampled by trawling remains still incomplete, notably in the Mediterranean Sea, one of the most threatened marine regions of the world. We investigated large spatio-temporal diversity patterns by analysing a dataset of 19,886 hauls from 10 to 800 m depth performed annually during the last two decades by standardised scientific bottom trawl field surveys across the Mediterranean Sea, within the MEDITS program. A multi-component (eight diversity indices) and multi-scale (local assemblages, biogeographic regions to basins) approach indicates that only the two most traditional components (species richness and evenness) were sufficient to reflect patterns in taxonomic, phylogenetic or functional richness and divergence. We also put into question the use of widely computed indices that allow comparing directly taxonomic, phylogenetic and functional diversity within a unique mathematical framework. In addition, demersal fish assemblages sampled by trawl do not follow a continuous decreasing longitudinal/latitudinal diversity gradients (spatial effects explained up to 70.6% of deviance in regression tree and generalised linear models), for any of the indices and spatial scales analysed. Indeed, at both local and regional scales species richness was relatively high in the Iberian region, Malta, the Eastern Ionian and Aegean seas, meanwhile the Adriatic Sea and Cyprus showed a relatively low level. In contrast, evenness as well as taxonomic, phylogenetic and functional divergences did not show regional hotspots. All studied diversity components remained stable over the last two decades. Overall, our results highlight the need to use complementary diversity indices through different

  20. Theoretical and numerical investigations towards a new geoid model for the Mediterranean Sea - The GEOMED2 project

    NASA Astrophysics Data System (ADS)

    Barzaghi, Riccardo; Vergos, Georgios S.; Albertella, Alberta; Carrion, Daniela; Cazzaniga, Noemi; Tziavos, Ilias N.; Grigoriadis, Vassilios N.; Natsiopoulos, Dimitrios A.; Bruinsma, Sean; Bonvalot, Sylvain; Lequentrec-Lalancette, Marie-Françoise; Bonnefond, Pascal; Knudsen, Per; Andersen, Ole; Simav, Mehmet; Yildiz, Hasan; Basic, Tomislav; Gil, Antonio J.

    2016-04-01

    The unique features of the Mediterranean Sea, with its large gravity variations, complex circulation, and geodynamic peculiarities have always constituted this semi-enclosed sea area as a unique geodetic, geodynamics and ocean laboratory. The main scope of the GEOMED 2 project is the collection of all available gravity, topography/bathymetry and satellite altimetry data in order to improve the representation of the marine geoid and estimate the Mean Dynamic sea surface Topography (MDT) and the circulation with higher accuracy and resolution. Within GEOMED2, the data employed are land and marine gravity data, GOCE/GRACE based Global Geopotential Models and a combination after proper validation of MISTRAL, HOMONIM and SRTM/bathymetry terrain models. In this work we present the results achieved for an inner test region spanning the Adriatic Sea area, bounded between 36o < φ < 48o and 10o < λ < 22o. Within this test region, the available terrain/bathymetry models have been evaluated in terms of their contribution to geoid modeling, the processing methodologies have been tested in terms of the provided geoid accuracy and finally some preliminary results on the MDT determination have been compiled. The aforementioned will server as the guide for the Mediterranean-wide marine geoid estimation. The processing methodology was based on the well-known remove-compute-restore method following both stochastic and spectral methods. Classic least-squares collocation (LSC) with errors has been employed, along with fast Fourier transform (FFT)-based techniques, the Least-Squares Modification of Stokes' Formula (KTH) method and windowed LSC. All methods have been evaluated against in-situ collocated GPS/Levelling geoid heights, using EGM2008 as a reference, in order to conclude on the one(s) to be used for the basin-wide geoid evaluation.

  1. Trophic status and meiofauna biodiversity in the Northern Adriatic Sea: Insights for the assessment of good environmental status.

    PubMed

    Bianchelli, Silvia; Pusceddu, Antonio; Buschi, Emanuela; Danovaro, Roberto

    2016-02-01

    The Descriptor 5 (Eutrophication) of the EU Marine Strategy Framework Directive aims at preventing the negative effects of eutrophication. However, in coastal systems all indicators based on water column parameters fail in identifying the trophic status and its effects on biodiversity and ecosystem functioning. We investigated benthic trophic status, in terms of sedimentary organic matter quantity, composition and quality, along with meiofaunal abundance, richness of taxa and community composition in three coastal sites (N Adriatic Sea) affected by different levels of anthropogenic stressors. We show that, on the basis of organic matter quantity and composition, the investigated areas can be classified from oligo-to mesotrophic, whereas using meiofauna as a descriptor, their environmental quality ranged from sufficient to moderately impacted. Our results show that the benthic trophic status based on organic matter variables, is not sufficient to provide a sound assessment of the environmental quality in marine coastal ecosystems. However, data reported here indicate that the integration of the meiofaunal variable allows providing robust assessments of the marine environmental status. PMID:26562451

  2. Radioactive contamination of cistern waters along the Croatian coast of the Adriatic Sea by [sup 90]Sr

    SciTech Connect

    Franic, Z.; Lokobauer, N.; Marovic, G. . Radiation Protection Unit)

    1999-07-01

    Measurements of radioactive contamination of water samples from cisterns collecting rainwater containing fission products from roofs and other surfaces have been carried out along the Croatian coast of the Adriatic sea since 1968. An exponential decline of radioactivity followed the nuclear moratorium. After the nuclear accident at Chernobyl, higher levels of [sup 137]Cs and [sup 90]Sr were detected again, with cistern waters being the only environmental samples in Croatia in which elevated [sup 90]Sr activities persisted for several years. For the pre-Chernobyl period, the observed mean residence time of [sup 90]Sr in cistern waters, estimated to be 6.2 [+-] 1.9 y, was similar to that calculated for fallout. Contrary, for the post-Chernobyl time, observed [sup 90]Sr mean residence time was calculated to be considerably shorter, reflecting the tropospheric mean residence time. The annual dose for the critical adult population received from [sup 90]Sr and [sup 137]Cs by drinking cistern water was estimated to be very small, in the 1990's less than few [micro]Sv y[sup [minus]1].

  3. Strategies for optimized geology-related seismic data processing in the geological interpretation of the Adriatic Sea

    SciTech Connect

    Agostinelli, E.; Boy, M.; Cardamone, M.; Carlini, A.

    1988-08-01

    New seismic surveys are usually preceded by methodical tests relative to specific exploration targets in the study area and provide results which are not widely applicable. If the main exploration targets of a basin are known, one can confidently choose a few representative sections and prepare a sequence of exhaustive processing tests concerning them. The relative data can be subsequently extrapolated to similar stratigraphic and structural situations in the basin. Such a knowledge base can be considerably enhanced by the use of the latest data processing techniques: 240-channel data treatment, multiple-events removal using advanced algorithms, pre- or post-stack time migrations, etc. This maximizes the efficiency of the seismic tool in terms of cost, time, and quality of results, making the derived geological interpretation more reliable. The central Adriatic Sea, due to the large amount of available data and experience acquired through years of exploration activity, represented a very good test area. In this basin a set of representative exploration targets on which to perform suitable processing tests was easily selected, and using the above-mentioned techniques they arrived at a better geological understanding of the area.

  4. Biomonitoring of a polluted coastal area (Bay of Muggia, Northern Adriatic Sea): A five-year study using transplanted mussels.

    PubMed

    Moschino, Vanessa; Del Negro, Paola; De Vittor, Cinzia; Da Ros, Luisa

    2016-06-01

    The subcellular effects of pollution were evaluated using two lysosomal biomarkers in mussels, Mytilus galloprovincialis, deployed periodically over a period of 5 years in a harbour area in the Bay of Muggia (Gulf of Trieste, North Adriatic Sea) that is strongly influenced by anthropogenic activities. Mussels were collected from a clean marine farm and analysed (sample T0). A sub-sample was transplanted to the harbour site (sample M) and analysed after about 12 weeks. An additional sub-sample was relocated within the farm as a control and was also tested at the end of the 12-week period (sample T1). The transplantation procedures were repeated twice yearly for 5 consecutive years, starting in 2009. Two well-established lysosomal biomarkers, i.e. lysosomal membrane stability and lipofuscin accumulation, were evaluated in hepatopancreas cells. The body condition index and mortality rate were also assessed. Moreover, various pollutants were determined in both mussel flesh, for a better comprehension of the biological response, and sediments, for a general characterization of the study area. As a whole, the applied biomarkers were found to be appropriate for determining the responses of mussels to environmental pollutant loads over time. Variations in lysosomal membrane stability and lipofuscin content were mostly related to total PAHs and metals respectively. Our results confirm the usefulness of active biomonitoring in evaluating pollution trends in marine coastal areas and in particular the value of lysosomal biomarkers as a rapid screening tool for highlighting pollutant effects at least at organism level. PMID:26874197

  5. Application of empirical model to predict background metal concentration in mixed carbonate-alumosilicate sediment (Adriatic Sea, Croatia).

    PubMed

    Felja, Igor; Romić, Marija; Romić, Davor; Bakić, Helena; Pikelj, Kristina; Juračić, Mladen

    2016-05-15

    A 96m long sediment core (S10-33) from the Mali Ston Channel (Adriatic Sea) showed large natural variation in carbonate share (between 1% and 95%) and concentration of elements. These variations indicate rather significant changes in fine-grained sediment that was deposited in this area during Younger Pleistocene and Holocene. Unaffected by anthropogenic influence, sediment in the core was used to determine background concentration of trace elements in sediment with various carbonate content. Here we propose a method of the normalization of trace elements to carbonate share, in order to assess natural/background concentration of metals in sediments consisting of carbonates and alumosilicates in various proportions. Six characteristic metals (Co, Cr, Cu, Ni, Pb, and Zn) that were normalized to carbonate share showed very good correlation, with much higher background concentrations in alumosilicate than in carbonate end member. Simple formulas were proposed to easily determine background concentration of these elements, in coastal and shelf depositional environments with mixed carbonate-alumosilicate sediments. PMID:26975609

  6. Influence of seasonal forcing on habitat use by bottlenose dolphins Tursiops truncatus in the Northern Adriatic Sea

    NASA Astrophysics Data System (ADS)

    Bearzi, Giovanni; Azzellino, Arianna; Politi, Elena; Costa, Marina; Bastianini, Mauro

    2008-12-01

    Bottlenose dolphins are the only cetaceans regularly observed in the northern Adriatic Sea, but they survive at low densities and are exposed to significant threats. This study investigates some of the factors that influence habitat use by the animals in a largely homogeneous environment by combining dolphin data with hydrological and physiographical variables sampled from oceanographic ships. Surveys were conducted year-round between 2003 and 2006, totalling 3,397 km of effort. Habitat modelling based on a binary stepwise logistic regression analysis predicted between 81% and 93% of the cells where animals were present. Seven environmental covariates were important predictors: oxygen saturation, water temperature, density anomaly, gradient of density anomaly, turbidity, distance from the nearest coast and bottom depth. The model selected consistent predictors in spring and summer. However, the relationship (inverse or direct) between each predictor and dolphin presence varied among seasons, and different predictors were selected in fall. This suggests that dolphin distribution changed depending on seasonal forcing. As the study area is relatively uniform in terms of bottom topography, habitat use by the animals seems to depend on complex interactions among hydrological variables, caused primarily by seasonal change and likely to determine shifts in prey distribution.

  7. Diagenesis and benthic fluxes of nutrients and metals during experimentally induced anoxia in the Gulf of Trieste (northern Adriatic Sea)

    NASA Astrophysics Data System (ADS)

    Koron, N.; Ogrinc, N.; Metzger, E.; Riedel, B.; Faganeli, J.

    2013-07-01

    Sequential nutrient regeneration and organic matter (OM) degradation in surface sediments of the Gulf of Trieste (northern Adriatic Sea) were examined using in situ benthic chambers under normoxic, anoxic and reoxic conditions. Intensive NH4+ and PO4- anoxic regeneration was subsequently slower in prolonged anoxia. NH4+ production was probably also a consequence of dissimilatory nitrate reduction to NH4+. The presence of anammox and laterally pumping of oxygenated water by benthic infauna explained the presence of NO3- in anoxia. Anoxic phases were characterized by enhanced dissolution of Sibiog, decreasing pore water Ca and Mg concentrations indicating carbonate precipitation and higher Fe and Mn concentrations as a result of reduction/respiration. Reoxygenation was characterized by enhanced bioturbation. Nitrification caused NH4+ decrease and P precipitated quickly as carbonate fluorapatite and FePO4. In addition adsorption of P onto Fe-hydroxides could also occur since Fe (and Mn) reoxidized quickly. Increased Ca levels suggested enhanced carbonate dissolution. Diffusive fluxes at the sediment-water interface (SWI), calculated from pore water modelling using diffusion-reaction model, revealed high anoxic NH4+ effluxes and Ca (and Mg) influxes. PO4- fluxes were very low and high NH4+/PO4- flux ratios in anoxic and reoxic phases suggested an excess of benthic inorganic N. Nutrient budgets at the SWI showed intensive anoxic recycling of inorganic N but low P and Si cycling in all redox phases.

  8. The reproductive cycle, size at maturity and fecundity of garfish ( Belone belone, L. 1761) in the eastern Adriatic Sea

    NASA Astrophysics Data System (ADS)

    Zorica, B.; Sinovčić, G.; Keč, V. Čikeš

    2011-12-01

    A recent study concerning the reproductive biology of the garfish ( Belone belone, L. 1761) has been carried out in the eastern part of the Adriatic Sea along the Croatian coastline. Specimens of the fish ( N = 3,393) were collected over a 6-year period (2003-2008). Their length varied between 20.8 and 75.4 cm (mean ± SD = 38.3 ± 7.94). Female garfish were dominant in larger length groups being most apparent during the resting phase of sexual cycle and in the peak of the spawning period, occurring in April and May. The sexual ratio of all specimens was m/f = 0.98. Males were prevalent in March—at the beginning of the highest spawning activities. Fifty percentage of the garfish population sexually matured at 28.5 cm of total length. Males and females reached their sexual maturity at 28.0 and 31.5 cm of total length, respectively. Spawning began in January peaking during March to May. According to their maturity stages, gonad weight and the gonadosomatic index, males began to spawn one month earlier (April) than females (May). The mean batch fecundity of garfish was 1,242.46 ± 843.64 of matured oocytes per ovary. Matured oocyte diameters ranged from 1.223 to 4.283 mm with the mean value of 2.269 ± 0.332 mm.

  9. Downward fluxes of elemental carbon, metals and polycyclic aromatic hydrocarbons in settling particles from the deep Ionian Sea (NESTOR site), Eastern Mediterranean

    NASA Astrophysics Data System (ADS)

    Theodosi, C.; Parinos, C.; Gogou, A.; Kokotos, A.; Stavrakakis, S.; Lykousis, V.; Hatzianestis, J.; Mihalopoulos, N.

    2012-12-01

    To assess sources and major processes controlling vertical transport of both anthropogenic and natural chemical species in deep basins of the Eastern Mediterranean Sea (SE Ionian Sea, Nestor site), we performed chemical characterization (elemental carbon, major and trace metals and polycyclic aromatic hydrocarbons) of marine sinking particles. Sediment traps were deployed at five successive depths, 700 m, 1200 m, 2000 m, 3200 m and 4300 m from the sea surface, during the period of May 2007 to October 2008. Fluxes of all measured species exhibited minimum values from January to March 2008 and maximum from April to September 2008, with an evident covariance revealing a common and rapid vertical transport mechanism from 700 m down to 4300 m depth. Crustal matter flux from atmospheric deposition plays an important role in the temporal variability of particulate matter with significant contribution from biogenic constituents namely the seasonal succession in the export of planktonic biomass, expressed by particulate organic carbon (POC), carbonates and biogenic Si fluxes (Stavrakakis et al., 2012). Tracers (elemental carbon, retene) of the devastating forest fires occurred in August 2007 in southern Greece, were detected at sediment trap material in all depths with a delay of 15 days at 4300 m, indicating a rapid and well-coupled transport of sinking particulate material between the sea-surface and deep layers of the Eastern Mediterranean Sea. Lateral inputs of pollutants at the deepest trap (4300 m) are probably of importance, due to the influence of deep Adriatic water at the study site.

  10. Baroclinic wind adjustment processes in the Mediterranean Sea

    NASA Astrophysics Data System (ADS)

    Pinardi, Nadia; Navarra, Antonio

    The wind-driven general circulation of the Mediterranean Sea is studied using a primitive equation model. The model uses a 0.25° horizontal resolution and eight or 16 levels in the vertical. The model uses the Mediterranean basin geometry, and the Strait of Gibraltar is closed. The vertical density structure is initialized with annual average data, and the temperature and salinity values are fixed at the surface to simulate perpetual annual mean conditions. The wind forcing consists of monthly mean climatological stresses. The results show that the general circulation of the Mediterranean Sea has a multiple time-scale character (seasonal excursions and steady state amplitudes are comparable) and it is composed by sub-basin scale gyres corresponding to the scale of the wind stress curl centers. The steady state circulation (annual mean average) is determined by a Sverdrup balacne modified by viscous effects. The unsteady vertically integrated transport circulation consists of sub-basin scale gyres similar to the steady state transport components, which amplify seasonally and the partial or total reversal of the currents in many subportions of the basin. The gyres can be stationary in position or propagating. This seasonal ocean response is partly constituted by Rossby modes due to the wind stress curl annual harmonic. The baroclinic circulation shows the seasonal shift of the North African Current from a position along the African coasts during winter to the center of the Balearic and Ionian basin during summer.

  11. The Mediterranean interannual variability in MEDRYS, a Mediterranean Sea reanalysis over 1992-2013

    NASA Astrophysics Data System (ADS)

    Beuvier, Jonathan; Hamon, Mathieu; Lellouche, Jean-Michel; Greiner, Eric; Alias, Antoinette; Arsouze, Thomas; Benkiran, Mounir; Béranger, Karine; Drillet, Yann; Sevault, Florence; Somot, Samuel

    2015-04-01

    The French research community on the Mediterranean Sea and the French operational ocean forecasting center Mercator Océan are gathering their skills and expertises in physical oceanography, ocean modelling, atmospheric forcings and data assimilation, to carry out a MEDiterranean Sea ReanalYsiS (MEDRYS) at high resolution for the period 1992-2013. The reanalysis is used to have a realistic description of the ocean state over the recent decades and it will help to understand the long-term water cycle over the Mediterranean basin in terms of variability and trends, contributing thus to the HyMeX international program. The ocean model used is NEMOMED12 [Lebeaupin Brossier et al., 2011, Oc. Mod., 2012, Oc. Mod.; Beuvier et al., 2012a, JGR, 2012b, Mercator Newsl.], a Mediterranean configuration of NEMO [Madec and the NEMO Team, 2008], with a 1/12° (about 7 km) horizontal resolution and 75 vertical z-levels with partial steps. It is forced by the 3-hourly atmospheric fluxes coming from an ALADIN-Climate simulation at 12 km of resolution [Herrmann et al., 2011, NHESS], driven by the ERA-Interim atmospheric reanalysis. The exchanges with the Atlantic Ocean are performed through a buffer zone, with a damping on 3D theta-S and on sea level towards the ORA-S4 oceanic reanalysis [Balmaseda et al., 2012, QJRMS]. This model configuration is used to carry a 34-year free simulation over the period 1979-2013. This free simulation is the initial state of the reanalysis in October 1992. It is also used to compute anomalies from which the data assimilation scheme derives required characteristic covariances of the ocean model. MEDRYS1 uses the current Mercator Océan operational data assimilation system [Lellouche et al., 2013, Oc.Sci.]. It uses a reduced order Kalman filter with a 3D multivariate modal decomposition of the forecast error. A 3D-Var scheme corrects biases in temperature and salinity for the slowly evolving large-scale. In addition, some modifications dedicated to the

  12. High-frequency cyclicity in the latest Messinian Adriatic foreland basin: Insight into palaeoclimate and palaeoenvironments of the Mediterranean Lago-Mare episode

    NASA Astrophysics Data System (ADS)

    Cosentino, D.; Cipollari, P.; Lo Mastro, S.; Giampaolo, C.

    2005-07-01

    Late Messinian Lago-Mare deposits show high-frequency cyclicity in the whole Mediterranean Basin. Both millimeter- and centimeter-scale cyclicities have been observed in several ODP sites as well as in stratigraphic sections from the Mediterranean borderland. We have analyzed a well-exposed late Messinian Lago-Mare section from the Adriatic side of the central Apennines (Italy). At the Fonte dei Pulcini section (SE Majella Mts.), millimeter- and centimeter-scale white-and-dark couplets have been observed in the field. A 50 cm regular-spaced sampling has been performed in the uppermost 53 m of the late Messinian Lago-Mare clays. On the 107 collected samples, geochemical (CaCO 3 content), mineralogical (XRD analyses), and micropalaeontological investigations have been performed. In addition, SEM and microprobe investigations as well as mineralogical and micropalaeontological analyses have been carried out on single lamina from a 34-cm-thick interval of millimeter-scale laminites. Besides the 10 3 cycles/m and 10 2 cycles/m frequencies observed in the field, spectral analyses performed on the CaCO 3 data set indicated other high-frequency cyclicities: 0.47 cycles/m, 0.35 cycles/m, and 0.17 cycles/m. Taking into account the estimated sedimentation rate, these frequencies correspond, respectively, to periodicities of: 1 year, 10 years, 2.1 kyr, 2.8 kyr, and 5.6 kyr. These sub-Milankovitch cyclicities have been related to annual and sunspot solar activity. The millimeter-scale couplets are interpreted as varves sedimented in an ephemeral water environment marginal to a perennial brackish water lagoonal basin. These varved sediments reflect a marked seasonality characterized by the alternation of arid and more humid climatic phases. The presence of high values of smectite (60-80%) in the clay minerals of the analyzed samples could be a consequence of these climatic oscillations from drier to moister conditions. The climatic scenario suggested in this paper for the late

  13. The impact of winter 2012 cold outbreak over the Northern Adriatic Sea dynamics: preliminary comparison among data and high resolution operational atmospheric models

    NASA Astrophysics Data System (ADS)

    Davolio, Silvio; Miglietta, Mario M.; Carniel, Sandro; Benetazzo, Alvise; Buzzi, Andrea; Drofa, Oxana; Falco, Pierpaolo; Fantini, Maurizio; Malguzzi, Piero; Ricchi, Antonio; Russo, Aniello; Paccagnella, Tiziana; Sclavo, Mauro

    2013-04-01

    exceptionally dense water formation, registered during the 2012 winter in the northern Adriatic region. During late January and early February, indeed, the basin was characterized by a persistent and exceptional cold anomaly responsible for large energy losses due to cold and extremely strong winds. Sea waters temperatures dropped to about 6°C and the Venice lagoon got partially covered by ice. In the period of interest, available measurements in the northern Adriatic Sea (temperature, salinity, density, wind speed, direction and inferred heat fluxes) were used, together with satellite measurements, to carry out a first semi-quantitative comparison among existing meteorological models implemented over the region. Namely, the work presents an intercomparison among three state-of-the-art, non-hydrostatic NWP models: COSMO-I7, WRF and MOLOCH. All models are run in operational mode, and their results are used by several Regional authorities and institutions for weather forecasting and support to civil protection decision. Therefore, this evaluation is a useful assessment preliminary to a full coupling of the above mentioned atmospheric models with existing ocean models already implemented in the region (e.g. ROMS in the COAWST system). Preliminary results show also some uncommon mesoscale structures reproduced by the models in the proximity of the central-south Italian coast, and highlight their possible influence on the local surface sea circulation. These effects will be soon explored by means of fully-coupled ocean-atmosphere models within on-going projects.

  14. Excess of (236)U in the northwest Mediterranean Sea.

    PubMed

    Chamizo, E; López-Lora, M; Bressac, M; Levy, I; Pham, M K

    2016-09-15

    In this work, we present first (236)U results in the northwestern Mediterranean. (236)U is studied in a seawater column sampled at DYFAMED (Dynamics of Atmospheric Fluxes in the Mediterranean Sea) station (Ligurian Sea, 43°25'N, 07°52'E). The obtained (236)U/(238)U atom ratios in the dissolved phase, ranging from about 2×10(-9) at 100m depth to about 1.5×10(-9) at 2350m depth, indicate that anthropogenic (236)U dominates the whole seawater column. The corresponding deep-water column inventory (12.6ng/m(2) or 32.1×10(12) atoms/m(2)) exceeds by a factor of 2.5 the expected one for global fallout at similar latitudes (5ng/m(2) or 13×10(12) atoms/m(2)), evidencing the influence of local or regional (236)U sources in the western Mediterranean basin. On the other hand, the input of (236)U associated to Saharan dust outbreaks is evaluated. An additional (236)U annual deposition of about 0.2pg/m(2) based on the study of atmospheric particles collected in Monaco during different Saharan dust intrusions is estimated. The obtained results in the corresponding suspended solids collected at DYFAMED station indicate that about 64% of that (236)U stays in solution in seawater. Overall, this source accounts for about 0.1% of the (236)U inventory excess observed at DYFAMED station. The influence of the so-called Chernobyl fallout and the radioactive effluents produced by the different nuclear installations allocated to the Mediterranean basin, might explain the inventory gap, however, further studies are necessary to come to a conclusion about its origin. PMID:27262827

  15. Freshening of the Marmara Sea prior to its post-glacial reconnection to the Mediterranean Sea

    NASA Astrophysics Data System (ADS)

    Aloisi, G.; Soulet, G.; Henry, P.; Wallmann, K.; Sauvestre, R.; Vallet-Coulomb, C.; Lécuyer, C.; Bard, E.

    2015-03-01

    During the last glaciation the Marmara Sea was isolated from the Mediterranean Sea because global sea level was below the depth of the Dardanelles sill. Prior to the postglacial reconnection to the Mediterranean Sea (∼14.7 cal kyr BP), the surface waters of the Marmara Sea were brackish (Marmara Lake). Freshening of a previously saline Marmara Sea could have happened via spill-out of brackish to fresh water from the surface water of the Black Sea through the Bosphorus Strait. This hypothesis has not been tested against alternative possibilities (salt flushing by river run-off and precipitation). Here we use the dissolved Cl- and stable isotope composition (δ18O and δD) of Marmara Sea sediment pore water to estimate the salinity and stable isotope composition of Marmara Lake bottom water and to evaluate possible freshening scenarios. We use a transport model to simulate pore water Cl-, δ18O and δD in Marmara Sea sediments in the past 130 kyr, which includes the last interglacial (130-75 cal kyr BP), the last glacial (75-14 cal kyr BP) and the current postglacial period. Our results show that the bottom waters of the Marmara Lake were brackish (∼ 4 ‰ salinity) and isotopically depleted (δ18O ∼ - 10.2 ‰ and δD ∼ - 70 ‰, respectively) compared to modern seawater. Their salinity and stable isotope ratios show that they are a mixture of Mediterranean waters and Danube-like waters implying that the freshening took place via spill-out of freshwater through the Bosphorus. Our modelling approach indicates that the transit of fresh water from glacial Eurasia to the Mediterranean via the Marmara Sea started at least 50 cal kyr BP, was continuous throughout most of the last glaciation and persisted up to the post glacial reconnection to the Mediterranean through the Dardanelles sill (14.7 cal kyr BP). These results are consistent with previously published micropaleontological and geochemical investigations of sediment cores that indicate lacustrine

  16. Earthquakes and tidal records in the Mediterranean sea: case studies

    NASA Astrophysics Data System (ADS)

    Vecchio, A.; Anzidei, M.; Carbone, V.; Capparelli, V.; Guerra, I.; Arena, G.

    2012-12-01

    We show and discuss the analysis of tidal data from some selected tide gauge stations located in the Mediterranean sea, including the Italian tide gauge network consisting in 30 stations. Our goal is to study the effects of large and moderate magnitude earthquakes on tidal oscillations. We focus on three seismic events: i) the March 11th, 2011, M 9.0 Tohoku-Oki earthquake, generating a giant tsunami offshore the Honshu island (Japan) that propagated in the Oceans. We show that the tidal stations located in the Mediterranean have recorded a weak signal that disturbed the daily tidal trends; ii) the May 21th, 2003, M 6.8 Boumerdès earthquake in northern Algeria, that generated a small tsunami event that reached the coast of Southern Europe; iii) the Dicember 17th, 2008, M 5.3 earthquake located in the Tyrrhenian sea. Finally, we also analyzed a sea level data set containing an anomalous tidal signal not related to earthquakes, felt along Thyrrhenian coast of Italy on July 2012. Tidal data were reduced for inverse barometric correction and analyzed by an advanced filtering technique that decomposes the records through oscillating modes, identifying the contributions at different timescales. In particular we focused on the dynamical behavior of the main tidal components (24 and 12 hours) and of low-frequency processes and trends.

  17. A Quantitative Assessment of the Sea Level Drop in the Messinian Mediterranean

    NASA Astrophysics Data System (ADS)

    Bartol, J.; Topper, R. P.

    2014-12-01

    In the Late Miocene progressive restriction of the gateway(s) between the Mediterranean Sea and the Atlantic Ocean initiated the Messinian Salinity Crisis (MSC). The restriction caused a salinity rise and the formation of extremely thick evaporite deposits within the Mediterranean basin. Subsequently, the closure of the connection between the Mediterranean Sea and Atlantic Ocean resulted in a dramatic sea level drop. The lithosphere adepts to changes in loads (sediments and water) on the surface by flexural adjustment of the Earth's surface. This can have a significant impact on the connectivity of basins and the temporal evolution of the sea level drop in each basin. The Mediterranean Sea is characterized by two deep basins with different amounts of river input (western/eastern Mediterranean basin) separated by the relatively shallow Sicily sill. The temporal evolution of the sea level drop in the western/eastern Mediterranean basin is therefore very sensitive to the temporal and spatial evolution of the Sicily gateway and hence flexure response of the earth surface due to the changes in waterload. However, studies of the MSC sea level drop haven't taken this flexural response into consideration (e.g. Meijer and Krijgsman, 2005). Here we use an elastic model (TISC) coupled with a simple hydrology model to calculate the temporal evolution of the sea level drop in and the flexural response of the western and eastern Mediterranean basins. Preliminary results show that when sea level drops below the Sicily sill, the rate of sea level increases in the western but decreases in the eastern Mediterranean. Following a relative sea level drop of ~1300 m, resulting in a flexural uplift of ~700m, the eastern Mediterranean reaches equilibrium. At the time the western Mediterranean (flexural uplift of ~900m) reaches an equilibrium it is almost completely desiccated. The magnitudes of the sea level drops and flexural response are, however, highly dependent on the hypsometry

  18. An objective reconstruction of the Mediterranean sea carbonate system

    NASA Astrophysics Data System (ADS)

    Lovato, Tomas; Vichi, Marcello

    2015-04-01

    An objective estimation of the current distribution of carbonate system variables for the Mediterranean Sea is proposed using empirical relationships derived from ship-based observations and combined with monthly climatological fields of hydrographic parameters. The high quality data of METEOR84/3 cruise were used to fit multiple linear regression models of Dissolved Inorganic Carbon (DIC) and Total Alkalinity (TA) from other hydrochemical parameters. These algorithms provided a robust estimation of DIC and TA, with corresponding Root Mean Squared Errors of 7.66 and 5.09 μmol/kg, by accounting only for potential temperature, salinity, pressure, and nitrate concentration. After the application of the identified regression models to a set of publicly available climatological fields, an objective assessment of the reconstructed carbonate system monthly distributions was derived and compared against different ship-based surveys. Results showed that the Mediterranean Sea interior was well reproduced with errors <14 μmol/kg, whereas the near surface layers still exhibited large uncertainties. The lower degree of confidence of this approach at the surface does not allow the direct application for studying anthropogenic CO2 trends, but some qualitative considerations were drawn from the comparison between the estimated inorganic carbon system and the available observational datasets. Most importantly, the present work showed that the estimated inventories are able to capture the linkages with the physical oceanic features of the system and we propose this method as an inexpensive solution to support the design of monitoring activities in the Mediterranean Sea, which is still poorly constrained by direct observations.

  19. Blooms of the potentially toxic diatom Pseudo-nitzschia calliantha Lundholm, Moestrup & Hasle in coastal waters of the northern Adriatic Sea (Croatia)

    NASA Astrophysics Data System (ADS)

    Marić, Daniela; Ljubešić, Zrinka; Godrijan, Jelena; Viličić, Damir; Ujević, Ivana; Precali, Robert

    2011-05-01

    The genus Pseudo-nitzschia contains more than 30 species, though most of them are discernible only on the basis of ultrastructural or genetic differences. We present a taxonomic study of Pseudo-nitzschia calliantha Lundhum, Hasle & Moestrup in the coastal waters of the northern Adriatic Sea together with domoic acid (DA) measurements on natural and breeding populations of shellfish. Sampling carried out monthly at 13 stations during 2007 showed Pseudo-nitzschia species to be present with high abundances during the entire year, forming blooms in coastal waters (reaching abundances of up to 1.2 × 10 6 cells L -1) during the late summer/early autumn, when they contributed up to 70% of the whole phytoplankton community. Ultrastructural examination provided evidence that the observed blooms were formed by the potentially toxic species P. calliantha. After the P. calliantha bloom, DA was detected at 3 stations along the north-eastern Adriatic coast with concentrations ranging from 0.11 to 1.32 μg g -1 in shellfish tissue. The distribution patterns of the species were analyzed statistically in order to explain the relationships between environmental variables and population dynamics. We here report on a mass appearance of the potentially toxic P. calliantha in the coastal waters of the northern Adriatic.

  20. Nursery areas of red mullet ( Mullus barbatus), hake ( Merluccius merluccius) and deep-water rose shrimp ( Parapenaeus longirostris) in the Eastern-Central Mediterranean Sea

    NASA Astrophysics Data System (ADS)

    Carlucci, Roberto; Giuseppe, Lembo; Porzia, Maiorano; Francesca, Capezzuto; Alessandra, Marano Chiara; Letizia, Sion; Teresa, Spedicato Maria; Nicola, Ungaro; Angelo, Tursi; D'Onghia, Gianfranco

    2009-08-01

    The spatial pattern of the nursery areas of red mullet ( Mullus barbatus), hake ( Merluccius merluccius) (Linnaeus, 1758) and deep-water rose shrimp ( Parapenaeus longirostris) (Lucas, 1846) was studied in the South Adriatic and North Ionian Seas (Eastern-Central Mediterranean) applying geostatistical techniques and data from time series trawl surveys conducted in the area. The analysed variables were: R (number of recruits/km 2) and R/Tot (fraction of recruits on the total sampled population). The structural analysis showed a spatial pattern of both variables characterized by continuity on a small scale. Predictions of nursery area localization with probability of finding recruits at different threshold values were obtained through median indicator kriging. For the red mullet the nurseries were mainly identified in the South Adriatic Sea off the Gargano peninsula and between Molfetta and Monopoli within 50 m in depth. The main concentration of hake juveniles was found to be between 100 and 200 m in depth along the Gargano peninsula and between Otranto and Santa Maria di Leuca, where a nursery of deep-water rose shrimp was also detected. An overlapping depth, between 100 and 200 m, was identified for hake and deep-water rose shrimp nurseries. Protection of these areas through limitations of fishing pressure is discussed.

  1. Factors controlling ebro deep-sea fan growth, Mediterranean Sea

    SciTech Connect

    Nelson, C.H.; Maldonado, A.; Alonso, B.; Palanques, A.; Ryan, W.B.F.; Kastens, K.; O'Connel, S.

    1985-01-01

    Tectonic, sediment-source and sea-level factors control depositional patterns of the Ebro deep-sea fan system. In unstable, steep continental slope terrain, mass movement of material results in wide gullied canyons and formation of non-channelized debris aprons. These fan channels develop low sinuosity and generally traverse the continental rise without feeding into depositional lobes because of steep gradients (1:50 to 1:100) and sediment draining into the subsiding Valencia Valley graben. An abundance of sediment input points from mass failure and many river-fed canyons contributes to a depositional pattern of side-by-side debris aprons and separate channel-levee complexes. When a large sediment supply feeds a channel for a relatively long period 1) fan valley sinuosity increases: 2) channel walls are modified through undercutting, slumping, and crevasse splays: 3) channel bifurcation occurs: 4) incipient depositional lobe formation begins. Lowering of sea levels in Late Pleistocene time permitted the access of coarse river sediment to slope valleys and promoted deposition of numerous turbidites and active growth of the fan. During the Holocene, when sea levels have been high, a regime of hemipelagic sedimentation, mass movement, and debris apron sedimentation has dominated.

  2. Fine-resolution simulation of surface current and sea ice in the Arctic Mediterranean Seas

    NASA Astrophysics Data System (ADS)

    Liu, Xiying; Zhang, Xuehong; Yu, Rucong; Liu, Hailong; Li, Wei

    2007-04-01

    A fine-resolution model is developed for ocean circulation simulation in the National Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics (LASG), Chinese Academy of Sciences, and is applied to simulate surface current and sea ice variations in the Arctic Mediterranean Seas. A dynamic sea ice model in elastic-viscous-plastic rheology and a thermodynamic sea ice model are employed. A 200-year simulation is performed and a dimatological average of a 10-year period (141st 150th) is presented with focus on sea ice concentration and surface current variations in the Arctic Mediterranean Seas. The model is able to simulate well the East Greenland Current, Beaufort Gyre and the Transpolar Drift, but the simulated West Spitsbergen Current is small and weak. In the March climatology, the sea ice coverage can be simulated well except for a bit more ice in east of Spitsbergen Island. The result is also good for the September scenario except for less ice concentration east of Greenland and greater ice concentration near the ice margin. The extra ice east of Spitsbergen Island is caused by sea ice current convergence forced by atmospheric wind stress.

  3. Deep-Sea Biodiversity in the Mediterranean Sea: The Known, the Unknown, and the Unknowable

    PubMed Central

    Danovaro, Roberto; Company, Joan Batista; Corinaldesi, Cinzia; D'Onghia, Gianfranco; Galil, Bella; Gambi, Cristina; Gooday, Andrew J.; Lampadariou, Nikolaos; Luna, Gian Marco; Morigi, Caterina; Olu, Karine; Polymenakou, Paraskevi; Ramirez-Llodra, Eva; Sabbatini, Anna; Sardà, Francesc; Sibuet, Myriam; Tselepides, Anastasios

    2010-01-01

    Deep-sea ecosystems represent the largest biome of the global biosphere, but knowledge of their biodiversity is still scant. The Mediterranean basin has been proposed as a hot spot of terrestrial and coastal marine biodiversity but has been supposed to be impoverished of deep-sea species richness. We summarized all available information on benthic biodiversity (Prokaryotes, Foraminifera, Meiofauna, Macrofauna, and Megafauna) in different deep-sea ecosystems of the Mediterranean Sea (200 to more than 4,000 m depth), including open slopes, deep basins, canyons, cold seeps, seamounts, deep-water corals and deep-hypersaline anoxic basins and analyzed overall longitudinal and bathymetric patterns. We show that in contrast to what was expected from the sharp decrease in organic carbon fluxes and reduced faunal abundance, the deep-sea biodiversity of both the eastern and the western basins of the Mediterranean Sea is similarly high. All of the biodiversity components, except Bacteria and Archaea, displayed a decreasing pattern with increasing water depth, but to a different extent for each component. Unlike patterns observed for faunal abundance, highest negative values of the slopes of the biodiversity patterns were observed for Meiofauna, followed by Macrofauna and Megafauna. Comparison of the biodiversity associated with open slopes, deep basins, canyons, and deep-water corals showed that the deep basins were the least diverse. Rarefaction curves allowed us to estimate the expected number of species for each benthic component in different bathymetric ranges. A large fraction of exclusive species was associated with each specific habitat or ecosystem. Thus, each deep-sea ecosystem contributes significantly to overall biodiversity. From theoretical extrapolations we estimate that the overall deep-sea Mediterranean biodiversity (excluding prokaryotes) reaches approximately 2805 species of which about 66% is still undiscovered. Among the biotic components investigated

  4. Deep-sea biodiversity in the Mediterranean Sea: the known, the unknown, and the unknowable.

    PubMed

    Danovaro, Roberto; Company, Joan Batista; Corinaldesi, Cinzia; D'Onghia, Gianfranco; Galil, Bella; Gambi, Cristina; Gooday, Andrew J; Lampadariou, Nikolaos; Luna, Gian Marco; Morigi, Caterina; Olu, Karine; Polymenakou, Paraskevi; Ramirez-Llodra, Eva; Sabbatini, Anna; Sardà, Francesc; Sibuet, Myriam; Tselepides, Anastasios

    2010-01-01

    Deep-sea ecosystems represent the largest biome of the global biosphere, but knowledge of their biodiversity is still scant. The Mediterranean basin has been proposed as a hot spot of terrestrial and coastal marine biodiversity but has been supposed to be impoverished of deep-sea species richness. We summarized all available information on benthic biodiversity (Prokaryotes, Foraminifera, Meiofauna, Macrofauna, and Megafauna) in different deep-sea ecosystems of the Mediterranean Sea (200 to more than 4,000 m depth), including open slopes, deep basins, canyons, cold seeps, seamounts, deep-water corals and deep-hypersaline anoxic basins and analyzed overall longitudinal and bathymetric patterns. We show that in contrast to what was expected from the sharp decrease in organic carbon fluxes and reduced faunal abundance, the deep-sea biodiversity of both the eastern and the western basins of the Mediterranean Sea is similarly high. All of the biodiversity components, except Bacteria and Archaea, displayed a decreasing pattern with increasing water depth, but to a different extent for each component. Unlike patterns observed for faunal abundance, highest negative values of the slopes of the biodiversity patterns were observed for Meiofauna, followed by Macrofauna and Megafauna. Comparison of the biodiversity associated with open slopes, deep basins, canyons, and deep-water corals showed that the deep basins were the least diverse. Rarefaction curves allowed us to estimate the expected number of species for each benthic component in different bathymetric ranges. A large fraction of exclusive species was associated with each specific habitat or ecosystem. Thus, each deep-sea ecosystem contributes significantly to overall biodiversity. From theoretical extrapolations we estimate that the overall deep-sea Mediterranean biodiversity (excluding prokaryotes) reaches approximately 2805 species of which about 66% is still undiscovered. Among the biotic components investigated

  5. Numerical Simulations of Precipitation Processes, Microphysics, and Microwave Radiative Properties of flood Producing Storms in Mediterranean & Adriatic Basins

    NASA Technical Reports Server (NTRS)

    Smith, Eric A.; Einaudi, Franco (Technical Monitor)

    2001-01-01

    A comprehensive understanding of the meteorological and microphysical nature of Mediterranean storms requires a combination of in situ data analysis, radar data analysis, and satellite data analysis, effectively integrated with numerical modeling studies at various scales. An important aspect of understanding microphysical controls of severe storms, is first understanding the meteorological controls under which a storm has evolved, and then using that information to help characterize the dominant microphysical processes. For hazardous Mediterranean storms, highlighted by the October 5-6, 1998 Friuli flood event in northern Italy, a comprehensive microphysical interpretation requires an understanding of the multiple phases of storm evolution. This involves intense convective development, Sratiform decay, orographic lifting, and sloped frontal lifting processes, as well as the associated vertical motions and thermodynamical instabilities governing physical processes that effect details of the size distributions and fall rates of the various types of hydrometeors found within the storm environment. This talk overviews the microphysical elements of a severe Mediterranean storm in such a context, investigated with the aid of TRMM satellite and other remote sensing measurements, but guided by a nonhydrostatic mesoscale model simulation of the Friuli flood event. The data analysis for this paper was conducted by my research groups at the Global Hydrology and Climate Center in Huntsville, AL and Florida State University in Tallahassee, and in collaboration with Dr. Alberto Mugnai's research group at the Institute of Atmospheric Physics in Rome. The numerical modeling was conducted by Professor Oreg Tripoli and Ms. Giulia Panegrossi at the University of Wisconsin in Madison, using Professor Tripoli's nonhydrostatic modeling system (NMS). This is a scalable, fully nested mesoscale model capable of resolving nonhydrostatic circulations from regional scale down to cloud scale

  6. Sea-level variability in the Mediterranean Sea from altimetry and tide gauges

    NASA Astrophysics Data System (ADS)

    Bonaduce, A.; Pinardi, N.; Oddo, P.; Spada, G.; Larnicol, G.

    2016-02-01

    Sea-level variability in the Mediterranean Sea was investigated by means of in-situ (tide-gauge) and satellite altimetry data over a period spanning two decades (from 1993 to 2012). The paper details the sea-level variations during this time period retrieved from the two data sets. Mean sea-level (MSL) estimates obtained from tide-gauge data showed root mean square differences (RMSDs) in the order of 40-50 % of the variance of the MSL signal estimated from satellite altimetry data, with a dependency on the number and quality of the in-situ data considered. Considering the individual time-series, the results showed that coastal tide-gauge and satellite sea-level signals are comparable, with RMSDs that range between 2.5 and 5 cm and correlation coefficients up to the order of 0.8. A coherence analysis and power spectra comparison showed that two signals have a very similar energetic content at semi-annual temporal scales and below, while a phase drift was observed at higher frequencies. Positive sea-level linear trends for the analysis period were estimated for both the mean sea-level and the coastal stations. From 1993 to 2012, the mean sea-level trend (2.44± 0.5 mm year^{-1} ) was found to be affected by the positive anomalies of 2010 and 2011, which were observed in all the cases analysed and were mainly distributed in the eastern part of the basin. Ensemble empirical mode decomposition showed that these events were related to the processes that have dominant periodicities of ˜ 10 years, and positive residual sea-level trend were generally observed in both data-sets. In terms of mean sea-level trends, a significant positive sea-level trend (> 95 %) in the Mediterranean Sea was found on the basis of at least 15 years of data.

  7. Down-core changes in molluscan death assemblages at Panzano Bay, an impacted area in the northern Adriatic Sea

    NASA Astrophysics Data System (ADS)

    Haselmair, Alexandra; Gallmetzer, Ivo; Stachowitsch, Michael; Tomasovych, Adam; Zuschin, Martin

    2016-04-01

    We use a historical ecology approach to shed light on the environmental history of the northern Adriatic Sea over the last hundreds to thousands of years. We focus on down-core changes in molluscan death assemblages, which serve as proxies for ecological shifts over time. The northern Adriatic Sea is particularly suited to study ecosystem modification under human pressure because it is among the most degraded marine ecosystems worldwide. We chose a sampling station in Panzano Bay, close the Isonzo River mouth and not far from the major industrial harbours of Trieste (Italy) and Koper (Slovenia), and traced down-core changes in molluscan community structure in correlation to major anthropogenic impacts that occurred here during the last centuries. Five sediment cores (1.5 m in length and diameters of 90 and 160 mm) were taken at a water depth of 12 m. We analysed grain size composition, the concentration of heavy metals and organic pollutants, and radiometrically dated the sediment using 210Pb. Furthermore, we dated shells of the abundant bivalve species Corbula gibba using 14C calibrated amino acid-racemisation (AAR). The whole molluscan community in the cores was analysed for species composition, abundance, taxonomic similarity, evidence for ecological interactions (i.e., frequencies of drilling predation) and taphonomic conditions of shells. The granulometric analysis shows that silt and clay dominate equally throughout the cores. Radiometric sediment dating revealed an average sedimentation rate of 2.5 mm/yr during the last 120 years. Shell dating points to a comparable overall core age, with only a few shell specimens being older than 500 years in the deepest core layer. In total, 10,452 mollusc individuals were analysed and 104 species identified. The most abundant bivalve species are Kurtiella bidentata, Corbula gibba and Abra nitida. Turritella communis and Nassarius pygmaeus are the most frequent gastropod species. Down-core changes in species composition

  8. Variability of PAHs and trace metals in the sediments in relation to environmental characteristics of the bottom layer in the middle Adriatic Sea

    NASA Astrophysics Data System (ADS)

    Grilli, Federica; Frapiccini, Emanuela; Campanelli, Alessandra; Guicciardi, Stefano; Marini, Mauro; Marasovic, Ivona; Grbec, Branka; Skejić, Sanda; Ujević, Ivana; Lušić, Jelena

    2015-04-01

    In the framework of the project PERSEUS (Policy-oriented marine Environmental Research in the Southern EUropean Seas), two interdisciplinary surveys were carried out in April 2013 and April 2014 in the middle Adriatic Sea along the Pescara-Sibenik transect (Jabuka Pits area) and Vieste-Split transect (Palagruza Sill area) with Croatian research vessel "Bios II" and the Italian research vessel "G. Dallaporta", respectively. The main objective of these research cruises was the implementation of the Marine Strategy Framework Directive (MSFD) in the Adriatic region for collecting physical, chemical and biological data in order to get a better understanding of whole Adriatic ecosystem. The two transects are already recognised as a key areas for the interception and the study of dense water modification (Zore-Armanda, 1963; Marini et al., 2006; Grilli et al., 2013). Due to seasonal circulation patterns, they are characterized by high temporal variability of the thermohaline structure (Grbec and Morović, 1997; Vilibić, et al., 2004) and other oceanographic parameters. Long term oceanographic records from the Middle Adriatic enable better understanding of the ecosystem response to changes of atmospheric and sea conditions through physical, chemical and biological processes (Marasović et al., 1995). Several oceanographic parameters relevant and useful for the ecosystem assessment of the two areas (temperature, salinity, density, fluorescence, oxygen, nutrients, chlorophyll, phyto- and zoo-plankton as well as selected pollutants , trace metals and Polycyclic Aromatic Hydrocarbons-PAHs in sediments) were collected. In the present work, the variations of PAHs and trace metals concentration in the marine sediments are presented in relation to the physical and chemical characteristics of the bottom layer. A constant influx of metal induces more intense accumulation of anthropogenic metals, especially Cd, in sediment from Jabuka Pit, and the metal content slightly increases

  9. Food web structure and vulnerability of a deep-sea ecosystem in the NW Mediterranean Sea

    NASA Astrophysics Data System (ADS)

    Tecchio, Samuele; Coll, Marta; Christensen, Villy; Company, Joan B.; Ramírez-Llodra, Eva; Sardà, Francisco

    2013-05-01

    There is increasing fishing pressure on the continental margins of the oceans, and this raises concerns about the vulnerability of the ecosystems thriving there. The current knowledge of the biology of deep-water fish species identifies potential reduced resilience to anthropogenic disturbance. However, there are extreme difficulties in sampling the deep sea, resulting in poorly resolved and indirectly obtained food-web relationships. Here, we modelled the flows and biomasses of a Mediterranean deep-sea ecosystem, the Catalan Sea continental slope at depths of 1000-1400 m. This is the first model of a deep-water ecosystem in the Mediterranean Sea. The objectives were to (a) quantitatively describe the food web structure of the ecosystem, (b) examine the role of key species in the ecosystem, and (c) explore the vulnerability of this deep-sea ecosystem to potential future fishing exploitation. We used the Ecopath with Ecosim (EwE) modelling approach and software to model the ecosystem. The trophic model included 18 consumers, a marine snow group, and a sediment detritus group. Trophic network analysis identified low levels of consumer biomass cycling and low system omnivory index when compared with expected values of marine ecosystems, and higher cycling and omnivory when compared with available EwE models of shallower areas of the Mediterranean Sea. The majority of flows in the ecosystem were concentrated at the trophic level of first-order consumers (TL 2). Benthic invertebrates and demersal sharks were identified to have key ecological roles in the ecosystem. We used the dynamic temporal model Ecosim to simulate expansion of the red-shrimp benthic trawl fishery that currently operates at shallower depths, down to 800 m depth. The simulations showed reductions in fish biomass and that the state of the deep continental slope ecosystem in the western Mediterranean seems to be the result of a long-term succession process, which has reached ecological stability, and is

  10. A new Bouguer gravity anomaly field for the Adriatic Sea and its application for the study of the crustal and upper mantle structure

    NASA Astrophysics Data System (ADS)

    Tassis, G. A.; Grigoriadis, V. N.; Tziavos, I. N.; Tsokas, G. N.; Papazachos, C. B.; Vasiljević, I.

    2013-05-01

    The purpose of this paper is the development of a new Bouguer anomaly map for the broader Adriatic Sea area to be used as geo-scientific tool which will answer questions mainly regarding the deep and intermediate depth structure of the Adriatic and its surrounding areas. As a first step, a consistent, high-resolution and accuracy free-air gravity anomaly database is created using all the available terrestrial and satellite altimetry data sources. The least-squares collocation (LSC) method is employed to validate the different gravity data sets through an appropriate covariance analysis and following the remove-compute-restore procedure (RCR) for the detailed study of the gravity spectrum. The finally generated gravity database has a resolution of a 0.0333° (˜3.2 km) in both latitude and longitude, while its external and internal accuracy is estimated to about ±5 mGal and ±0.5 mGal, respectively. Based on the derived free-air gravity database a new Bouguer gravity anomaly database is determined at the same resolution for the wider region of the Adriatic Sea. Comparison with existing results confirms the reliability of the new Bouguer map for the study area, mainly due to the combination of both land and sea data. The derived Bouguer anomaly map can support different kind of geophysical investigations of both local and regional structure of the study region. As an example three density models are constructed along selected cross sections extracted from the Bouguer anomaly database, in order to obtain structural information for the crustal-upper mantle structure of the region and draw relevant conclusions. The obtained results show that the Bouguer map can provide important information for the lower-crustal/upper-mantle depth range but also helps to constrain the 2D geometry of the shallow geological units, in very good agreement with the observed surface geology and the current understanding of the geotectonic setting of the area.

  11. A multidisciplinary environmental integrated approach to better understand the Tegnue Reefs formation, offshore Chioggia, Northern Adriatic Sea.

    NASA Astrophysics Data System (ADS)

    Bergamasco, Andrea; Donnici, Sandra; Tosi, Luigi; Tagliapietra, Davide; Zaggia, Luca; Bonaldo, Davide; Braga, Federica; Da Lio, Cristina; Keppel, Erica; Lorenzetti, Giuliano; Manfè, Giorgia; Franceschini, Gianluca; Giovanardi, Otello; Carol, Eleonora; Fornaro, Elena; Grant, Carley

    2014-05-01

    , and benthic invertebrates like bryozoans, mollusks, serpulids and corals also contribute to the final building of the status of Tegnue's environment, but we want to demonstrate that the in first stage of consolidation abiotic phenomena could have played a major role. In order to prove our thesis a series of ground water sampling as well as rock sampling and sediment cores were carried out. The poster illustrates the overall ongoing program as well as some work in progress and first results from field cruise. Acknowledgments This work was supported by the Municipality of Chioggia through the Tegnue Project and partially by the Flagship Project RITMARE - The Italian Research for the Sea - coordinated by the Italian National Research Council and funded by the Italian Ministry of Education, University and Research within the National Research Program 2011-2013, and by the Scientific Cooperation Agreement between the CONICET (Argentina) - CNR (Italy), Program 2013-2014, Project 'Fresh-saltwaters in high-value coastlands: from the hydrogeophysical/geochemical characterization of the present interactions to the modeling quantification of the expected effects of climate changes'. References - Bonardi, M., Tosi, L. 2000. Indagini preliminari su alcune formazioni di sabbie cementate nella laguna di Venezia. In: La Ricerca Scientifica Per Venezia. Il Progetto Sistema Lagunare Veneziano, Modellistica del Sistema Lagunare Studio di Impatto Ambientale. Istituto Veneto di Scienze, Lettere ed Arti, Vol. II, Tomo II, p. 967-974, Venezia, ISBN: 88-86166-82-6. - Bonardi, M., Tosi, L., Rizzetto, F., Brancolini, G., Baradello, L. 2006. Effects of climate changes on the late Pleistocene and Holocene sediments of the Venice Lagoon, Italy. Journal of Coastal Research, SI 39, 279-284. - Casellato S., Stefanon A. 2008. Coralligenous habitat in the northern Adriatic Sea: an overview. Marine Ecology, 29: 321-341. - Gabbianelli, G., Colantoni, P., Degetto, S., Dinelli, E., Lucchini, F. 1997

  12. Tidal notches in Mediterranean Sea: a comprehensive analysis

    NASA Astrophysics Data System (ADS)

    Antonioli, Fabrizio; Lo Presti, Valeria; Rovere, Alessio; Ferranti, Luigi; Anzidei, Marco; Furlani, Stefano; Mastronuzzi, Giuseppe; Orru, Paolo E.; Scicchitano, Giovanni; Sannino, Gianmaria; Spampinato, Cecilia R.; Pagliarulo, Rossella; Deiana, Giacomo; de Sabata, Eleonora; Sansò, Paolo; Vacchi, Matteo; Vecchio, Antonio

    2015-07-01

    Recent works (Evelpidou et al., 2012) suggest that the modern tidal notch is disappearing worldwide due sea level rise over the last century. In order to assess this hypothesis, we measured modern tidal notches in several of sites along the Mediterranean coasts. We report observations on tidal notches cut along carbonate coasts from 73 sites from Italy, France, Croatia, Montenegro, Greece, Malta and Spain, plus additional observations carried outside the Mediterranean. At each site, we measured notch width and depth, and we described the characteristics of the biological rim at the base of the notch. We correlated these parameters with wave energy, tide gauge datasets and rock lithology. Our results suggest that, considering 'the development of tidal notches the consequence of midlittoral bioerosion' (as done in Evelpidou et al., 2012) is a simplification that can lead to misleading results, such as stating that notches are disappearing. Important roles in notch formation can be also played by wave action, rate of karst dissolution, salt weathering and wetting and drying cycles. Of course notch formation can be augmented and favoured also by bioerosion which can, in particular cases, be the main process of notch formation and development. Our dataset shows that notches are carved by an ensemble rather than by a single process, both today and in the past, and that it is difficult, if not impossible, to disentangle them and establish which one is prevailing. We therefore show that tidal notches are still forming, challenging the hypothesis that sea level rise has drowned them.

  13. Diversity, distribution and population size structure of deep Mediterranean gorgonian assemblages (Menorca Channel, Western Mediterranean Sea)

    NASA Astrophysics Data System (ADS)

    Grinyó, Jordi; Gori, Andrea; Ambroso, Stefano; Purroy, Ariadna; Calatayud, Clara; Dominguez-Carrió, Carlos; Coppari, Martina; Lo Iacono, Claudio; López-González, Pablo J.; Gili, Josep-Maria

    2016-06-01

    Gorgonians are a key group of organisms in benthic marine communities with a wide bathymetric and geographical distribution. Although their presence on continental shelves and slopes has been known for more than 100 years, knowledge concerning the ecology of deep gorgonian species is still in a very preliminary stage. To overcome this situation, gorgonian assemblages located at 40-360 m depth were studied over a large geographical area on the continental shelf and upper slope of the Menorca Channel (Western Mediterranean Sea). A quantitative analysis of video transects recorded by a manned submersible and a remotely operated vehicle, were used to examine the diversity, distribution and demography of gorgonian species. Results showed high gorgonian diversity within this depth range (a total of nine species were observed) compared to Mediterranean coastal areas. Gorgonian assemblages on the continental shelf and upper slope were mostly monospecific (respectively 73% and 76% of occupied sampling units contained one single species), whereas shelf edge assemblages were highly multispecific (92% of occupied sampling units contained several species). This contrasts with the monospecificity of Mediterranean coastal gorgonian assemblages. Gorgonian populations on the continental shelf were mostly dominated by small colonies (88% of measured colonies) with few intermediate and large colonies (12% of measured colonies). In deeper areas small colonies were still dominant (60% of measured colonies), but intermediate and large colonies were much more abundant (40% of measured colonies). This suggests high recruitment rates on the continental shelf, but perturbations (trammel nets, long lines and strong storms) may limit the presence of intermediate and large colonies. Conversely, on the shelf edge and upper slope a more stable environment may allow colonies to reach larger dimensions. The identification and ecological characterization of these deep assemblages further extends

  14. Longitudinal variability of the biogeochemical role of Mediterranean aerosols in the Mediterranean Sea

    NASA Astrophysics Data System (ADS)

    Ternon, E.; Guieu, C.; Ridame, C.; L'Helguen, S.; Catala, P.

    2010-11-01

    The Mediterranean Sea is a semi-enclosed basin characterized by a strong thermal stratification during summer during which the atmosphere is the main source of new nutrients to the nutrient-depleted surface layer. From aerosol sampling and microcosm experiments performed during the TransMed BOUM cruise (June-July 2008) we showed that: (i) the Mediterranean atmosphere composition (Al, Fe, P) was homogeneous over ~28° of longitude and was a mixture with a constant proportion of anthropogenic contribution and a variable but modest contribution of crustal aerosols. This quite stable composition over a one month period and a long transect (~2500 km) allowed to define the Mediterranean atmospheric "background" that characterizes the summer season in the absence of major Saharan event and forest fires, (ii) primary production significantly increased at all tested stations after aerosols addition collected on-board and after Saharan dust analog addition, indicating that both additions relieved on-going (co)-limitations. Although both additions significantly increased the N2 fixation rates at the western station, diazotrophic activity remained very low (~0.2 nmol N L-1 d-1), (iii) due to the presence of anthropogenic particles, the probable higher solubility of nutrients associated with mixed aerosols (crustal + anthropogenic contribution), conferred a higher fertilizing potential to on-board collected aerosol as compared to Saharan dust analog. Finally, those experiments showed that atmospheric inputs from a mixed atmospheric event ("summer rain" type) or from a high-intensity Saharan event would induce comparable response by the biota in the stratified Mediterranean SML, during summer.

  15. Longitudinal variability of the biogeochemical role of Mediterranean aerosols in the Mediterranean Sea

    NASA Astrophysics Data System (ADS)

    Ternon, E.; Guieu, C.; Ridame, C.; L'Helguen, S.; Catala, P.

    2011-05-01

    The Mediterranean Sea is a semi-enclosed basin characterized by a strong thermal stratification during summer during which the atmosphere is the main source of new nutrients to the nutrient-depleted surface layer. From aerosol sampling and microcosm experiments performed during the TransMed BOUM cruise (June-July 2008) we showed that: (i) the Mediterranean atmosphere composition (Al, Fe, P) was homogeneous over ~28° of longitude and was a mixture with a constant proportion of anthropogenic contribution and a variable but modest contribution of crustal aerosols. This quite stable composition over a one month period and a long transect (~2500 km) allowed to define the Mediterranean atmospheric "background" that characterizes the summer season in the absence of major Saharan event and forest fires, (ii) primary production significantly increased at all tested stations after aerosols addition collected on-board and after Saharan dust analog addition, indicating that both additions relieved on-going (co)-limitations. Although both additions significantly increased the N2 fixation rates at the western station, diazotrophic activity remained very low (~0.2 nmol N L-1 d-1), (iii) due to the presence of anthropogenic particles, the probable higher solubility of nutrients associated with mixed aerosols (crustal + anthropogenic contribution), conferred a higher fertilizing potential to on-board collected aerosol as compared to Saharan dust analog. Finally, those experiments showed that atmospheric inputs from a mixed atmospheric event ("summer rain" type) or from a high-intensity Saharan event would induce comparable response by the biota in the stratified Mediterranean SML, during summer.

  16. Factors affecting fish assemblages associated with gas platforms in the Mediterranean Sea

    NASA Astrophysics Data System (ADS)

    Consoli, Pierpaolo; Romeo, Teresa; Ferraro, Maria; Sarà, Gianluca; Andaloro, Franco

    2013-03-01

    Understanding the role played by offshore platforms in marine ecosystems is acquiring increasing importance worldwide. In this work, underwater visual census techniques were applied to describe spatial and temporal patterns of fish assemblages associated with extractive platforms. Data were collected during three seasons according to the following spatial factors: Location (Adriatic and Ionian Seas), Depth (0-6 m and 12-18 m) and Distance from the platform (external and internal). Both univariate and multivariate analyses showed highly significant differences for each factor assessed in this study, as well as for the interaction among said factors. Results indicated that artificial structures in both the Adriatic and Ionian Seas act as artificial reefs attracting reef-dwelling or partially reef-dwelling species, which are not present far from the platforms in open waters. Results also showed significant differences between Ionian and Adriatic fish assemblages, with a higher mean density of fish and a greater mean number of species in the latter basin. Boops boops, Chromis chromis and several species belonging to the Blennidae family most contributed to these differences. This is likely due to the eutrophication that involves the coast of the northern and central Adriatic, allowing a high production of fish, especially planctivorous. Thanks to the eutrophication, platforms located in this basin are characterized by a greater abundance of fouling organisms which offer a perfect habitat for cryptobenthic species, such as Blennids. Moreover, Thalassoma pavo and Scorpaena maderensis, thermophilic species, were more abundant in the Ionian platforms than in the Adriatic ones thus contributing to the dissimilarities between these two basins. Present results could bear strong implications for the environmental management of drilling and production activities in different basins. Assessing biodiversity in these highly complex contexts is a challenge for the near future, and

  17. Seismicity of the Earth 1900‒2013 Mediterranean Sea and vicinity

    USGS Publications Warehouse

    Herman, Matthew W.; Hayes, Gavin P.; Smoczyk, Gregory M.; Turner, Rebecca; Turner, Bethan; Jenkins, Jennifer; Davies, Sian; Parker, Amy; Sinclair, Allison; Benz, Harley M.; Furlong, Kevin P.; Villaseñor, Antonio

    2015-01-01

    The Mediterranean region is seismically active due to the convergence of the Africa Plate with the Eurasia plate. Present day Africa-Eurasia motion ranges from ~4 millimeters per year (mm/yr) in a northwest-southeast direction in the western Mediterranean to ~10 mm/yr (north-south) in the eastern Mediterranean. The Africa-Eurasia plate boundary is complex, and includes extensional and translational zones in addition to the dominant convergent regimes characterized by subduction and continental collision. This convergence began at approximately 50 million years ago and was associated with the closure of the Tethys Sea; the Mediterranean Sea is all that remains of the Tethys. The highest rates of seismicity in the Mediterranean region are found along the Hellenic subduction zone of southern Greece and the North Anatolian Fault Zone of northwestern Turkey, but significant rates of current seismicity and large historical earthquakes have occurred throughout the region spanning the Mediterranean Sea.

  18. Invasion Pathway of the Ctenophore Mnemiopsis leidyi in the Mediterranean Sea

    PubMed Central

    Ghabooli, Sara; Shiganova, Tamara A.; Briski, Elizabeta; Piraino, Stefano; Fuentes, Veronica; Thibault-Botha, Delphine; Angel, Dror L.; Cristescu, Melania E.; MacIsaac, Hugh J.

    2013-01-01

    Gelatinous zooplankton outbreaks have increased globally owing to a number of human-mediated factors, including food web alterations and species introductions. The invasive ctenophore Mnemiopsis leidyi entered the Black Sea in the early 1980s. The invasion was followed by the Azov, Caspian, Baltic and North Seas, and, most recently, the Mediterranean Sea. Previous studies identified two distinct invasion pathways of M. leidyi from its native range in the western Atlantic Ocean to Eurasia. However, the source of newly established populations in the Mediterranean Sea remains unclear. Here we build upon our previous study and investigate sequence variation in both mitochondrial (Cytochrome c Oxidase subunit I) and nuclear (Internal Transcribed Spacer) markers in M. leidyi, encompassing five native and 11 introduced populations, including four from the Mediterranean Sea. Extant genetic diversity in Mediterranean populations (n = 8, Na = 10) preclude the occurrence of a severe genetic bottleneck or founder effects in the initial colonizing population. Our mitochondrial and nuclear marker surveys revealed two possible pathways of introduction into Mediterranean Sea. In total, 17 haplotypes and 18 alleles were recovered from all surveyed populations. Haplotype and allelic diversity of Mediterranean populations were comparable to populations from which they were likely drawn. The distribution of genetic diversity and pattern of genetic differentiation suggest initial colonization of the Mediterranean from the Black-Azov Seas (pairwise FST = 0.001–0.028). However, some haplotypes and alleles from the Mediterranean Sea were not detected from the well-sampled Black Sea, although they were found in Gulf of Mexico populations that were also genetically similar to those in the Mediterranean Sea (pairwise FST = 0.010–0.032), raising the possibility of multiple invasion sources. Multiple introductions from a combination of Black Sea and native region sources

  19. Invasion pathway of the Ctenophore Mnemiopsis leidyi in the Mediterranean Sea.

    PubMed

    Ghabooli, Sara; Shiganova, Tamara A; Briski, Elizabeta; Piraino, Stefano; Fuentes, Veronica; Thibault-Botha, Delphine; Angel, Dror L; Cristescu, Melania E; Macisaac, Hugh J

    2013-01-01

    Gelatinous zooplankton outbreaks have increased globally owing to a number of human-mediated factors, including food web alterations and species introductions. The invasive ctenophore Mnemiopsis leidyi entered the Black Sea in the early 1980s. The invasion was followed by the Azov, Caspian, Baltic and North Seas, and, most recently, the Mediterranean Sea. Previous studies identified two distinct invasion pathways of M. leidyi from its native range in the western Atlantic Ocean to Eurasia. However, the source of newly established populations in the Mediterranean Sea remains unclear. Here we build upon our previous study and investigate sequence variation in both mitochondrial (Cytochrome c Oxidase subunit I) and nuclear (Internal Transcribed Spacer) markers in M. leidyi, encompassing five native and 11 introduced populations, including four from the Mediterranean Sea. Extant genetic diversity in Mediterranean populations (n = 8, N a = 10) preclude the occurrence of a severe genetic bottleneck or founder effects in the initial colonizing population. Our mitochondrial and nuclear marker surveys revealed two possible pathways of introduction into Mediterranean Sea. In total, 17 haplotypes and 18 alleles were recovered from all surveyed populations. Haplotype and allelic diversity of Mediterranean populations were comparable to populations from which they were likely drawn. The distribution of genetic diversity and pattern of genetic differentiation suggest initial colonization of the Mediterranean from the Black-Azov Seas (pairwise F ST = 0.001-0.028). However, some haplotypes and alleles from the Mediterranean Sea were not detected from the well-sampled Black Sea, although they were found in Gulf of Mexico populations that were also genetically similar to those in the Mediterranean Sea (pairwise F ST = 0.010-0.032), raising the possibility of multiple invasion sources. Multiple introductions from a combination of Black Sea and native region sources

  20. Difference of mercury bioaccumulation in red mullets from the north-western Mediterranean and Black seas.

    PubMed

    Harmelin-Vivien, M; Cossa, D; Crochet, S; Bănaru, D; Letourneur, Y; Mellon-Duval, C

    2009-05-01

    The relationships between total mercury (Hg) concentration and stable nitrogen isotope ratio (delta(15)N) were evaluated in Mullus barbatus barbatus and M. surmuletus from the Mediterranean Sea and M. barbatus ponticus from the Black Sea. Mercury concentration in fish muscle was six times higher in the two Mediterranean species than in the Black Sea one for similar sized animals. A positive correlation between Hg concentration and delta(15)N occurred in all species. Increase in Hg concentration with delta(15)N was high and similar in the two Mediterranean fishes and much lower in the Black Sea species. Since this was neither related to trophic level difference between species nor to methylmercury (MeHg) concentration differences between the north-western Mediterranean and the Black Sea waters, we suggested that the higher primary production of the Black Sea induced a dilution of MeHg concentration at the base of the food webs. PMID:19201429

  1. Variability of PAHs and trace metals in the sediments in relation to environmental characteristics of the bottom layer in the middle Adriatic Sea

    NASA Astrophysics Data System (ADS)

    Grilli, Federica; Frapiccini, Emanuela; Campanelli, Alessandra; Guicciardi, Stefano; Marini, Mauro; Marasovic, Ivona; Grbec, Branka; Skejić, Sanda; Ujević, Ivana; Lušić, Jelena

    2015-04-01

    In the framework of the project PERSEUS (Policy-oriented marine Environmental Research in the Southern EUropean Seas), two interdisciplinary surveys were carried out in April 2013 and April 2014 in the middle Adriatic Sea along the Pescara-Sibenik transect (Jabuka Pits area) and Vieste-Split transect (Palagruza Sill area) with Croatian research vessel "Bios II" and the Italian research vessel "G. Dallaporta", respectively. The main objective of these research cruises was the implementation of the Marine Strategy Framework Directive (MSFD) in the Adriatic region for collecting physical, chemical and biological data in order to get a better understanding of whole Adriatic ecosystem. The two transects are already recognised as a key areas for the interception and the study of dense water modification (Zore-Armanda, 1963; Marini et al., 2006; Grilli et al., 2013). Due to seasonal circulation patterns, they are characterized by high temporal variability of the thermohaline structure (Grbec and Morović, 1997; Vilibić, et al., 2004) and other oceanographic parameters. Long term oceanographic records from the Middle Adriatic enable better understanding of the ecosystem response to changes of atmospheric and sea conditions through physical, chemical and biological processes (Marasović et al., 1995). Several oceanographic parameters relevant and useful for the ecosystem assessment of the two areas (temperature, salinity, density, fluorescence, oxygen, nutrients, chlorophyll, phyto- and zoo-plankton as well as selected pollutants , trace metals and Polycyclic Aromatic Hydrocarbons-PAHs in sediments) were collected. In the present work, the variations of PAHs and trace metals concentration in the marine sediments are presented in relation to the physical and chemical characteristics of the bottom layer. A constant influx of metal induces more intense accumulation of anthropogenic metals, especially Cd, in sediment from Jabuka Pit, and the metal content slightly increases

  2. Distribution and assessment of marine debris in the deep Tyrrhenian Sea (NW Mediterranean Sea, Italy).

    PubMed

    Angiolillo, Michela; di Lorenzo, Bianca; Farcomeni, Alessio; Bo, Marzia; Bavestrello, Giorgio; Santangelo, Giovanni; Cau, Angelo; Mastascusa, Vincenza; Cau, Alessandro; Sacco, Flavio; Canese, Simonepietro

    2015-03-15

    Marine debris is a recognized global ecological concern. Little is known about the extent of the problem in the Mediterranean Sea regarding litter distribution and its influence on deep rocky habitats. A quantitative assessment of debris present in the deep seafloor (30-300 m depth) was carried out in 26 areas off the coast of three Italian regions in the Tyrrhenian Sea, using a Remotely Operated Vehicle (ROV). The dominant type of debris (89%) was represented by fishing gears, mainly lines, while plastic objects were recorded only occasionally. Abundant quantities of gears were found on rocky banks in Sicily and Campania (0.09-0.12 debris m(-2)), proving intense fishing activity. Fifty-four percent of the recorded debris directly impacted benthic organisms, primarily gorgonians, followed by black corals and sponges. This work provides a first insight on the impact of marine debris in Mediterranean deep ecosystems and a valuable baseline for future comparisons. PMID:25604749

  3. Haloarchaeal communities in the crystallizers of two adriatic solar salterns.

    PubMed

    Pasić, Lejla; Ulrih, Natasa Poklar; Crnigoj, Miha; Grabnar, Miklavz; Velikonja, Blagajana Herzog

    2007-01-01

    Solar salterns operate only for short dry periods of the year in the north shore of the Adriatic Sea because of its relatively humid and cold Mediterranean climate. In a previous paper, we showed that the NaCl precipitation ponds (crystallizers) of Northern Adriatic Secovlje salterns have different haloarchaeal populations from those typically found in dry and hot climates such as Southern Spain. To check whether there is a common pattern of haloarchaeal diversity in these less extreme conditions, diversity in crystallizers of other Adriatic solar salterns in Ston, Croatia was ascertained by molecular and culture methods. In addition, the cultivation approach was used to further describe haloarchaeal diversity in both salterns. Over the period of two solar salt collection seasons, isolates related to species of the genera Haloferax, Haloarcula, and Haloterrigena were recovered from both salterns. Within the same sampling effort, relatives of the genus Halorubrum and a Natrinema-like isolate were cultivated from Slovenian Secovlje salterns while Halobacterium related isolates were obtained from the Croatian Ston salterns. Concurrent with our previous findings, a library of Croatian saltern crystallizer PCR-amplified 16S rRNA genes was dominated by sequences related to the genus Halorubrum. The microbial community structure was similar in both salterns but diversity indices showed greater values in Slovenian salterns when compared with Croatian salterns. PMID:17496945

  4. Performance evaluation of Wavewatch III in the Mediterranean Sea

    NASA Astrophysics Data System (ADS)

    Mentaschi, Lorenzo; Besio, Giovanni; Cassola, Federico; Mazzino, Andrea

    2015-06-01

    For this study, we analyzed the performance of the wave model Wavewatch III® forced by a limited area atmospheric model in the Mediterranean Sea. The simulation results have been compared to buoy measurements through single point statistical indicators such as normalized bias and symmetrically normalized root mean square error. A performance evaluation of the growth-dissipation source terms and their reference parameterizations was carried out on seventeen case studies corresponding to storms in the Northern Tyrrhenian Sea and off the Mediterranean Spanish coast. The source terms introduced by Ardhuin et al. (2010) proved to be the best overall choice, although they led to an overestimation in the significant wave height under calm conditions and to an underestimation under severe conditions. A sensitivity analysis in the parameter space was performed within the neighborhood of the reference parameterization of Ardhuin et al. (2010), and a calibration was carried out to reduce the overall positive bias in the significant wave height. Furthermore, to investigate the effect from the wind forcing resolution, wind data with different resolutions was used in a sensitivity analysis. Because mesoscale features are relevant to the overall Mediterranean wave dynamics, we carried out a further investigation into the impact of the resolution on a different set of ten case studies characterized by strong mesoscale patterns. A comparison of the simulations with the measurements using single point statistical indicators shows that the high resolution results are affected by the so-called double penalty effect, although in some cases, they apparently provide a better qualitative description of the event. Finally, a hindcast covering 32 years (from 1979 to 2010) was developed using a reference parameterization from Ardhuin et al. (2010) and its calibrated variant. An analysis of the performance of the calibrated parameterization on the hindcast dataset reveals that it performs

  5. Seasonal changes in technological and nutritional quality of Mytilus galloprovincialis from suspended culture in the Gulf of Trieste (North Adriatic Sea).

    PubMed

    Bongiorno, Tiziana; Iacumin, Lucilla; Tubaro, Franco; Marcuzzo, Eva; Sensidoni, Alessandro; Tulli, Francesca

    2015-04-15

    Nutritional quality parameters, microbiological and technological quality indicators (condition index, meat yield and water-holding capacity) of blue mussel, Mytilus galloprovincialis, reared in the North Adriatic Sea were characterised at monthly intervals over a 1 year period. Contents of protein (7.5-11.6 g/100 g), lipid (1.0-2.2 g/100 g) and ash (2.2-3.3 g/100 g) varied significantly accordingly to condition index (6-15%). n-3 PUFAs were the predominant fatty acids (38.7-45.9% of fatty acids) and docosahesaenoic and eicosapentaenoic acids were the most abundant (167 and 93.3 mg/100 g, respectively). Glycine, glutamic and aspartic acids accounted for 40% of total amino acids. All samples exhibited limited concentrations of Cr, Mn, Ni, Cu and Zn, as well as Na. M. galloprovincialis from the North Adriatic Sea showed the highest technological and nutritional quality, considering also the inter-annual variability, in late spring, which corresponds to the period immediately before gamete release. PMID:25466033

  6. Functional structure of marine benthic assemblages using Biological Traits Analysis (BTA): A study along the Emilia-Romagna coastline (Italy, North-West Adriatic Sea)

    NASA Astrophysics Data System (ADS)

    Paganelli, Daniele; Marchini, Agnese; Occhipinti-Ambrogi, Anna

    2012-01-01

    The functional diversity index has shown that the functional diversity of the macrobenthic community increased along a spatial gradient of distance from the Po river delta (Emilia-Romagna coast, Italy, North-Adriatic Sea), which suggests that riverine inputs have a detrimental effect on community functioning. This study focuses on two different depths along a southward gradient of increasing distance from the Po river delta where the Po river is the main source of freshwater and nutrient inputs in the North-Adriatic Sea. A Biological Traits Analysis (BTA) was used to examine a dataset of 156 soft-bottom macrobenthic species that were collected at eight stations in this area. Instead of comparing communities on the basis of their taxonomic composition, BTA uses a series of life history, morphological and behavioural characteristics of species to indicate aspects of their ecological functioning. The variability of the Emilia-Romagna dataset was governed by relatively few biological traits: growth form, trophic group, type of movement, habit, adult mobility and bioturbation activity. The community closer to the coastline was mainly composed of moderately mobile vermiform organisms with burrowing or tube-dwelling behaviour, and deposit feeding behaviour. However, the offshore community was mainly characterized by organisms with a laterally compressed or globose body and tube-dwelling behaviour; filter feeders and deposit feeders were dominant.

  7. On the use of a coupled ocean-atmosphere-wave model during an extreme cold air outbreak over the Adriatic Sea

    NASA Astrophysics Data System (ADS)

    Ricchi, Antonio; Miglietta, Mario Marcello; Falco, Pier Paolo; Benetazzo, Alvise; Bonaldo, Davide; Bergamasco, Andrea; Sclavo, Mauro; Carniel, Sandro

    2016-05-01

    An intense cold air outbreak affected the northern Adriatic Sea during winter 2012, determining an exceptional persistence of northeasterly Bora wind over the basin, which lasted for about 3 weeks. The cold air coming from the Balkans produced icing in the Venice lagoon and very intense snowfall in the Apennines Mountains and even near the coasts. In order to understand the importance and role of air-sea interactions for the evolution of the atmospheric fields, simulations with the Weather Research and Forecasting (WRF) model encompassing the whole period have been performed using sea surface temperature (SST) fields with an increasing level of complexity. Starting from a large-scale static sea temperature, the SST in the initial and boundary conditions has been progressively made more realistic. First, a more refined field, retrieved from a satellite radiometer was used; then, the same field was updated every 6 h. Next, the effect of including a simplified 1D ocean model reproducing the Oceanic Mixed Layer (OML) evolution has been tested. Finally, the potential improvements coming from a coupled description of atmosphere-ocean and atmosphere-ocean-waves interactions have been explored within the Coupled Ocean-Atmosphere-Wave Sediment Transport (COAWST) modeling system. Results highlight that the energy exchange between air and sea does not significantly impact the atmospheric fields, in particular 10 m wind and 2 m temperature, also because of the geography of the basin and the predominance of synoptic-scale flow in intense events of Bora, in the northern Adriatic. However, when sensible and latent heat fluxes, which are dependent on atmospheric and oceanic variables, are analyzed, the more realistic representation of SST drastically improves the model performances.

  8. Deviation of Baltic, Adriatic and Black Sea level from the global mean during the 20th century: analysis of the main factors involved and a high-end projection to the end of 21st century.

    NASA Astrophysics Data System (ADS)

    Scarascia, Luca; Lionello, Piero

    2016-04-01

    The main goal of this work is to investigate which are the main factors determining interannual sea level variability of Baltic, Adriatic and Black seas, and to which extent the sea level of these three basins can deviate from the global mean. The three basins selected are semi-enclosed marginal seas connected with the adjacent seas by narrow straits. 13 sea level timeseries in Baltic Sea, 7 in Adriatic Sea and 5 in Black Sea provided by PSMSL, allowed us to compute a single seamless sea level timeseries representative for each basin from 1900 and for the entire 20th century, using statistical tools (PCA and Least Square method). Comparison with satellite data in the period 1993-2009, confirms that timeseries so computed are good representations of the observed sea level, with correlation values of 0.97, 0.87 and 0.72 for Baltic, Adriatic and Black Sea respectively. At basin scale the sea level has been decomposed in various contributions that have been separately analyzed: local effect of pressure, steric effect due to temperature and salinity variation, boundary forcing, wind effect and river discharge. The annual cycles and their variability, show that the largest contribution is due to the wind for the Adriatic Sea and for the Baltic Sea. In these two basins the inverse Barometer effect plays a minor role and the steric factor is almost negligible. The wind seems to play a negligible role on Black Sea, where the Danube river discharge plays an important role. A linear regression model, built considering large scale sea level pressure distribution as predictor, is capable to explain a further percentage of sea level variability variability (about 20%) left after subtracting all the factors considered above. Sea level of the Baltic and Black Sea show a significant positive correlation (0.3 about) revealing the likely influence of an external common forcing. Past sea level variability shows no strong evidences of large deviation from the global mean sea level

  9. Interannual differences for sea turtles bycatch in Spanish longliners from Western Mediterranean Sea.

    PubMed

    Báez, José C; Macías, David; García-Barcelona, Salvador; Real, Raimundo

    2014-01-01

    Recent studies showed that regional abundance of loggerhead and leatherback turtles could oscillate interannually according to oceanographic and climatic conditions. The Western Mediterranean is an important fishing area for the Spanish drifting longline fleet, which mainly targets swordfish, bluefin tuna, and albacore. Due to the spatial overlapping in fishing activity and turtle distribution, there is an increasing sea turtle conservation concern. The main goal of this study is to analyse the interannual bycatch of loggerhead and leatherback turtles by the Spanish Mediterranean longline fishery and to test the relationship between the total turtle by-catch of this fishery and the North Atlantic Oscillation (NAO). During the 14 years covered in this study, the number of sea turtle bycatches was 3,940 loggerhead turtles and 8 leatherback turtles, 0.499 loggerhead turtles/1000 hooks and 0.001014 leatherback turtles/1000 hooks. In the case of the loggerhead turtle the positive phase of the NAO favours an increase of loggerhead turtles in the Western Mediterranean Sea. However, in the case of leatherback turtle the negative phase of the NAO favours the presence of leatherback turtle. This contraposition could be related to the different ecophysiological response of both species during their migration cycle. PMID:24764769

  10. Interannual Differences for Sea Turtles Bycatch in Spanish Longliners from Western Mediterranean Sea

    PubMed Central

    Báez, José C.; García-Barcelona, Salvador

    2014-01-01

    Recent studies showed that regional abundance of loggerhead and leatherback turtles could oscillate interannually according to oceanographic and climatic conditions. The Western Mediterranean is an important fishing area for the Spanish drifting longline fleet, which mainly targets swordfish, bluefin tuna, and albacore. Due to the spatial overlapping in fishing activity and turtle distribution, there is an increasing sea turtle conservation concern. The main goal of this study is to analyse the interannual bycatch of loggerhead and leatherback turtles by the Spanish Mediterranean longline fishery and to test the relationship between the total turtle by-catch of this fishery and the North Atlantic Oscillation (NAO). During the 14 years covered in this study, the number of sea turtle bycatches was 3,940 loggerhead turtles and 8 leatherback turtles, 0.499 loggerhead turtles/1000 hooks and 0.001014 leatherback turtles/1000 hooks. In the case of the loggerhead turtle the positive phase of the NAO favours an increase of loggerhead turtles in the Western Mediterranean Sea. However, in the case of leatherback turtle the negative phase of the NAO favours the presence of leatherback turtle. This contraposition could be related to the different ecophysiological response of both species during their migration cycle. PMID:24764769

  11. Extreme winter 2012 in the Adriatic: an example of climatic effect on the BiOS rhythm

    NASA Astrophysics Data System (ADS)

    Gačić, M.; Civitarese, G.; Kovačević, V.; Ursella, L.; Bensi, M.; Menna, M.; Cardin, V.; Poulain, P.-M.; Cosoli, S.; Notarstefano, G.; Pizzi, C.

    2014-02-01

    Adriatic and Ionian Seas are Mediterranean sub-basins linked through the Bimodal Oscillating System mechanism responsible for decadal reversals of the Ionian basin-wide circulation. Altimetric maps showed that the last cyclonic mode started in 2011 but unexpectedly in 2012 reversed to anticyclone. We related this "premature" inversion to extremely strong winter in 2012, which caused the formation of very dense Adriatic waters, flooding Ionian flanks in May and inverting the bottom pressure gradient. Using Lagrangian float measurements, the linear regression between the sea surface height and three isopycnal depths suggests that the southward deep-layer flow coincided with the surface northward geostrophic current and the anti-cyclonic circulation regime. Density variations at depth in the north-western Ionian revealed the arrival of Adriatic dense waters in May and maximum density in September. Comparison between the sea level height in the north-western Ionian and in the basin centre showed that in coincidence with the arrival of the newly formed Adriatic dense waters the sea level lowered in the north-western flank inverting the surface pressure gradient. Toward the end of 2012, the density gradient between the basin flanks and its centre went to zero, coinciding with the weakening of the anticyclonic circulation and eventually with its return to the cyclonic pattern. Thus, the premature and transient reversal of Ionian surface circulation originated from the extremely harsh winter in the Adriatic, resulting in the formation and spreading of highly dense bottom waters. The present study highlights the remarkable sensitiveness of the Adriatic-Ionian BiOS to climatic forcing.

  12. Extreme winter 2012 in the Adriatic: an example of climatic effect on the BiOS rhythm

    NASA Astrophysics Data System (ADS)

    Gačić, M.; Civitarese, G.; Kovačević, V.; Ursella, L.; Bensi, M.; Menna, M.; Cardin, V.; Poulain, P.-M.; Cosoli, S.; Notarstefano, G.; Pizzi, C.

    2014-06-01

    Adriatic and Ionian seas are Mediterranean sub-basins linked through the Bimodal Oscillating System mechanism responsible for decadal reversals of the Ionian basin-wide circulation. Altimetric maps showed that the last cyclonic mode started in 2011 but unexpectedly in 2012 reversed to anticyclonic. We related this "premature" inversion to the extremely strong winter in 2012, which caused the formation of very dense Adriatic waters, flooding Ionian flanks in May and inverting the bottom pressure gradient. Using Lagrangian float measurements, the linear regression between the sea surface height and three isopycnal depths suggests that the southward deep-layer flow coincided with the surface northward geostrophic current and the anticyclonic circulation regime. Density variations at depth in the northwestern Ionian revealed the arrival of Adriatic dense waters in May and maximum density in September. Comparison between the sea level height in the northwestern Ionian and in the basin centre showed that in coincidence with the arrival of the newly formed Adriatic dense waters the sea level was lowered in the northwestern flank, inverting the surface pressure gradient. Toward the end of 2012, the density gradient between the basin flanks and its centre went to zero, coinciding with the weakening of the anticyclonic circulation and eventually with its return to the cyclonic pattern. Thus, the premature and transient reversal of Ionian surface circulation originated from the extremely harsh winter in the Adriatic, resulting in the formation and spreading of highly dense bottom waters. The present study highlights the remarkable sensitiveness of the Adriatic-Ionian BiOS to climatic forcing.

  13. Post-convection spreading phase in the Northwestern Mediterranean Sea

    NASA Astrophysics Data System (ADS)

    Testor, P.; Gascard, J.-C.

    2006-05-01

    This is a study about the spreading of newly formed deep waters following open ocean deep convection in the Northwestern Mediterranean Sea. The main results are from the SOFARGOS large scale float experiment initiated in 1994-1995. During the SOFARGOS project, CTD stations and Lagrangian observations of ocean currents were carried out in the Gulf of Lion from December 1994 to July 1995. Hydrological observations confirmed that deep water formation occurred very early during winter 1994-1995 (late December, early January) in conjunction with atmospheric cooling, deep convection penetrating down to 2000 m in the so-called Medoc area. Numerous eddies (both anticyclonic and cyclonic) drifted away from the convection area and advected newly formed deep waters far away from the source region. In particular, compact anticyclones appeared to be the most coherent (long-lived) eddies and capable of transporting newly formed Western Mediterranean Deep Waters several hundreds of kilometers away from the convection area. Characterized by an inner core of about 5 km in radius, these eddies are submesoscale features in the outer domain and appear as key elements of the open ocean convection processes. During their long journeys, these eddies interacted with larger scale features such as the Northern Boundary Current, the North Balearic Front, topographic Rossby waves, and Sardinian eddies. These interactions influenced the long-term behavior of the eddies (mean drift, composition) and represented an important part of (1) the spreading phase following deep convection and (2) the large scale thermohaline circulation.

  14. Drilling predation on molluscs in the northern Adriatic Sea: Spatial variability and temporal trends over the last millennia

    NASA Astrophysics Data System (ADS)

    Dengg, Markus; Wurzer, Sandra; Gallmetzer, Ivo; Haselmair, Alexandra; Zuschin, Martin

    2016-04-01

    Competition and predation are essential ecological factors influencing biodiversity. In a palaeontological context, the rate of predatory interactions between animal species is difficult to reconstruct because traces of predation are rarely incorporated into the fossil record. In the marine environment, the calcareous shells of molluscs, however, have good, long-time preservation potential, and predation in this group is often exerted by carnivorous gastropods that drill holes into mollusc shells. The prey's perforated shells remain in the sediment and can be used to study rates and intensities of predatory interactions in past marine molluscan communities. Differences in drilling frequencies along a sediment core not only reflect changes in local species richness and predation pressure, but may also mirror ecosystem changes through space and time. This makes the analysis of drilling predation an important tool when investigating the historical ecology of marine habitats. We used 1.5-m-long sediment cores from seven shelf locations spread throughout the northern Adriatic Sea basin to investigate regional and down-core variations in drilling frequencies. In total, about 54,000 bivalve and 40,000 gastropod shells were analysed to determine the following parameters: 1) overall drill frequency (DF), the proportion of shells drilled by predators; 2) edge drill frequency (EDF, only in bivalve shells), the proportion of shells with drilling traces at the shell edge; 3) multiple drill frequency (MDF), the percentage of individuals with more than one drill hole, 4) incomplete drill frequency (IDF), the percentage of shells unsuccessfully drilled; 5) prey effectiveness (PE), the proportion of individuals resisting the predator's attacks. Total drill frequency across all cores is 18% for bivalves and 13% for gastropods, but there are marked regional differences, with minima in the Po Delta (5%) and maxima in Panzano Bay (24%). Edge-drilled shells and multiple drill holes on

  15. Delta-associated molluscan life and death assemblages in the northern Adriatic Sea: Implications for paleoecology, regional diversity and conservation

    PubMed Central

    Weber, Kristina; Zuschin, Martin

    2013-01-01

    Life–death (LD) studies of shelly macrofauna are important to evaluate how well a fossil assemblage can reflect the original living community, but can also serve as a proxy for recent ecological shifts in marine habitats and in practice this has to be distinguished using taphonomic preservation pattern and estimates of time-averaging. It remains to be rigorously evaluated, however, how to distinguish between sources of LD disagreement. In addition, death assemblages (DAs) also preserve important information on regional diversity which is not available from single censuses of the life assemblages (LAs). The northern Adriatic Sea is an ecosystem under anthropogenic pressure, and we studied the distribution and abundance of living and dead bivalve and gastropod species in the physically stressful environments (tidal flat and shallow sublittoral soft bottoms) associated with the delta of the Isonzo River (Gulf of Trieste). Specifically we evaluated the fidelity of richness, evenness, abundance, habitat discrimination and beta diversity. A total of 10,740 molluscs from fifteen tidal flat and fourteen sublittoral sites were analyzed for species composition and distribution of living and dead molluscs. Of 78 recorded species, only eleven were numerically abundant. There were many more dead than living individuals and rarefied species richness in the DA was higher at all spatial scales, but the differences are lower in habitats and in the region than at individual stations. Evenness was always higher in death assemblages, and probably due to temporally more variable LAs the differences are stronger in the sublittoral habitats. Distinct assemblages characterized intertidal and sublittoral habitats, and the distribution and abundance of empty shells generally corresponded to that of the living species. Death assemblages have lower beta diversity than life assemblages, but empty shells capture compositional differences between habitats to a higher degree than living shells

  16. Picoplankton community structure before, during and after convection event in the offshore waters of the southern Adriatic Sea

    NASA Astrophysics Data System (ADS)

    Najdek, M.; Paliaga, P.; Šilović, T.; Batistić, M.; Garić, R.; Supić, N.; Ivančić, I.; Ljubimir, S.; Korlević, M.; Jasprica, N.; Hrustić, E.; Dupčić-Radić, I.; Blažina, M.; Orlić, S.

    2013-11-01

    This paper documents the picoplankton community's response to changes in oceanographic conditions in the period between October 2011 and September 2012 at two stations belonging to South Adriatic Pit (SAP). The recorded data include the community's abundance, composition, prokaryotic production rates and bacterial metabolic capacity. The aforementioned interval included an intense sea cooling with formation of exceptionally, record-breaking dense water. We documented an especially intense winter convection episode that completely diluted the core of Levantine intermediate waters (LIW) in a large area encompassing the SAP's center and its margin. During this convection event the whole picoplankton community had significantly higher abundances with a recorded picoeukaryotic peak at the SAP margin. In the post-convection phase in March prokaryotic heterotrophic production strongly increased in the entire SAP area (up to 50 times; 456.8 nM C day-1). The autotrophic biomass increase (up to 5 times; 4.86 μg L-1) and a disruption of a close correspondence between prokaryotic heterotrophic biomass production and cell replication rates were observed only in the center of the SAP, which was not under the influence of LIW. At the SAP's margin such an effect was attenuated by LIW, since the waters affected by LIW were characterized by decreased concentrations of dissolved inorganic nitrogen, decreased autotrophic biomasses and by increased bacterial biomass production balanced with cell replication rates as well as by the domination of Synechococcus among autotrophic picoplankton. Metabolic capacity was the lowest in spring when autotrophic biomass largely increased, while the highest levels found in the pre-convection phase (October 2011) suggests that the system was more oligotrophic before than after the convection event. Furthermore, we showed that metabolic capacity is a trait of bacterial community independent of environmental conditions and tightly linked to cell

  17. Mediterranean space-time extremes of wind wave sea states

    NASA Astrophysics Data System (ADS)

    Barbariol, Francesco; Carniel, Sandro; Sclavo, Mauro; Marcello Falcieri, Francesco; Bonaldo, Davide; Bergamasco, Andrea; Benetazzo, Alvise

    2014-05-01

    Traditionally, wind wave sea states during storms have been observed, modeled, and predicted mostly in the time domain, i.e. at a fixed point. In fact, the standard statistical models used in ocean waves analysis rely on the implicit assumption of long-crested waves. Nevertheless, waves in storms are mainly short-crested. Hence, spatio-temporal features of the wave field are crucial to accurately model the sea state characteristics and to provide reliable predictions, particurly of wave extremes. Indeed, the experimental evidence provided by novel instrumentations, e.g. WASS (Wave Acquisition Stereo System), showed that the maximum sea surface elevation gathered in time over an area, i.e. the space-time extreme, is larger than that one measured in time at a point, i.e. the time extreme. Recently, stochastic models used to estimate maxima of multidimensional Gaussian random fields have been applied to ocean waves statistics. These models are based either on Piterbarg's theorem or Adler and Taylor's Euler Characteristics approach. Besides a probability of exceedance of a certain threshold, they can provide the expected space-time extreme of a sea state, as long as space-time wave features (i.e. some parameters of the directional variance density spectrum) are known. These models have been recently validated against WASS observation from fixed and moving platforms. In this context, our focus was modeling and predicting extremes of wind waves during storms. Thus, to intensively gather space-time extremes data over the Mediterranean region, we used directional spectra provided by the numerical wave model SWAN (Simulating WAves Nearshore). Therefore, we set up a 6x6 km2 resolution grid entailing most of the Mediterranean Sea and we forced it with COSMO-I7 high resolution (7x7 km2) hourly wind fields, within 2007-2013 period. To obtain the space-time features, i.e. the spectral parameters, at each grid node and over the 6 simulated years, we developed a modified version

  18. Sea-Salt Aerosol Forecasts Compared with Wave and Sea-Salt Measurements in the Open Mediterranean Sea

    NASA Astrophysics Data System (ADS)

    Kishcha, P.; Starobinets, B.; Bozzano, R.; Pensieri, S.; Canepa, E.; Nickovie, S.; di Sarra, A.; Udisti, R.; Becagli, S.; Alpert, P.

    2012-03-01

    Sea-salt aerosol (SSA) could influence the Earth's climate acting as cloud condensation nuclei. However, there were no regular measurements of SSA in the open sea. At Tel-Aviv University, the DREAM-Salt prediction system has been producing daily forecasts of 3-D distribution of sea-salt aerosol concentrations over the Mediterranean Sea (http://wind.tau.ac.il/saltina/ salt.html). In order to evaluate the model performance in the open sea, daily modeled concentrations were compared directly with SSA measurements taken at the tiny island of Lampedusa, in the Central Mediterranean. In order to further test the robustness of the model, the model performance over the open sea was indirectly verified by comparing modeled SSA concentrations with wave height measurements collected by the ODAS Italia 1 buoy and the Llobregat buoy. Model-vs.-measurement comparisons show that the model is capable of producing realistic SSA concentrations and their day-today variations over the open sea, in accordance with observed wave height and wind speed.

  19. Freshwater mass balance and exchange of water masses with the open sea: the Mljet Lakes (Croatia, Adriatic Sea)

    NASA Astrophysics Data System (ADS)

    Martincic, Urska; Bezak, Nejc; Zagar, Dusan; Makovec, Tihomir; Lucic, Davor; Onofri, Vladimir; Malacic, Vlado

    2016-04-01

    Two karstic seawater lakes (Veliko - Big and Malo - Small Lake) located in the National Park Mljet on the Mljet Island in Croatia were investigated in this study. The Small and the Big Lake cover 0.25 and 1.45 km2, respectively. The two lakes are connected to each other and to the sea by narrow channels. The connecting channel between the Big Lake and the sea is 12 m wide and 3 m deep. The connection to the Small Lake leads through another artificial channel (2.7 m wide and 0.8 m deep). The average salinity of the Big and the Small lake is 37.75 and 36.9, respectively, and the average salinity of the open sea is 38.5. While previous studies have been conducted due to the lakes' unique ecosystem and the karstic characteristics of the area, the main aim of this study was to determine the freshwater mass balance and exchange of water masses with the nearby sea. Several measurement campaigns were performed between 2008 and 2015 when meteorological parameters as well as salinity, water temperature and water velocities in both lakes and the channels were observed. A perpetual year was determined using available meteorological data. The contribution of the surface runoff to both lakes was modelled using the hydrological rainfall-runoff HEC-HMS model. Curve number parameter was estimated using the CLC Corine Land cover and geomorphological maps. Evaporation from the lake was calculated using the Verburg, Kondo and Coare equations. We found that the annual evaporation approximately equals the annual rainfall to the lake surface (cca. 550-600 mm). From the hydrological model and the difference between precipitation and evaporation from the lake surface we calculated the annual net excess of freshwater between 0.5 106 and 0.7 106 m3. The average salinity in both lakes is lower than the salinity in the sea; therefore, we hypothesize that the excess water should be discharged either through the channel between the Big Lake and the open sea or through underwater karstic sink

  20. Comparison of the adjoint and adjoint-free 4dVar assimilation of the hydrographic and velocity observations in the Adriatic Sea

    NASA Astrophysics Data System (ADS)

    Yaremchuk, Max; Martin, Paul; Koch, Andrey; Beattie, Christopher

    2016-01-01

    Performance of the adjoint and adjoint-free 4-dimensional variational (4dVar) data assimilation techniques is compared in application to the hydrographic surveys and velocity observations collected in the Adriatic Sea in 2006. Assimilating the data into the Navy Coastal Ocean Model (NCOM) has shown that both methods deliver similar reduction of the cost function and demonstrate comparable forecast skill at approximately the same computational expense. The obtained optimal states were, however, significantly different in terms of distance from the background state: application of the adjoint method resulted in a 30-40% larger departure, mostly due to the excessive level of ageostrophic motions in the southern basin of the Sea that was not covered by observations.

  1. Low sea-level stand emplacement of megaturbidites in the western and eastern Mediterranean Sea

    NASA Astrophysics Data System (ADS)

    Rothwell, R. G.; Reeder, M. S.; Anastasakis, G.; Stow, D. A. V.; Thomson, J.; Kähler, G.

    2000-09-01

    Piston cores from the Balearic and Herodotus Abyssal Plains in the Mediterranean Sea show that the Late Pleistocene to Holocene sedimentary sequence is dominated by turbidite muds. On each plain, one turbidite bed is conspicuous by its thickness, and this bed can be correlated basinwide on the basis of geochemical compositional analysis and its apparent correspondence with a distinct acoustically transparent layer on high-resolution seismic records. These megabeds on the two plains represent megaturbidites of very large volume (300-600 km 3 each) and are shown by AMS radiocarbon dating to have been emplaced during the last low stand of sea-level at the height of the last glacial maximum. The megabed on the Balearic Abyssal Plain is derived from the southern European margin and is the main sedimentation event over the last 120 ka. It emplaced as much material as was deposited by smaller flows during the previous 25 ka. Sedimentation rate curves for the Balearic Abyssal Plain show that falling sea-level correlates with increased terrigenous deposition, and that gross sedimentation rates in the basin increased as sea level fell from 120-18 ka due to more frequent emplacement of distal turbidites. The Herodotus Abyssal Plain megabed is derived from the Libyan-Egyptian continental shelf west of the Nile Delta and was the dominant sedimentation event in this basin during the past 60 kyr. High-resolution seismic profiles from the Ionian and Sirte Abyssal Plains in the central Mediterranean also suggest possible low sea-level emplacement of megabeds in these regions. Available evidence suggests widespread emplacement of megaturbidites throughout the Mediterranean at the last glacial maximum. Although the triggering mechanisms for these events remain speculative, catastrophic destabilisation of the margin after a long period of accumulation with an increased rate of sediment supply is suggested.

  2. Seasonal differences in intraseasonal and interannual variability of Mediterranean Sea surface temperature

    NASA Astrophysics Data System (ADS)

    Zveryaev, Igor I.

    2015-04-01

    Sea surface temperature (SST) data from the NOAA OI SST data set for 1982-2011 are used to investigate intraseasonal and interannual variability of Mediterranean SST during winter and summer seasons. It is shown that during winter the intraseasonal SST fluctuations are larger than the interannual SST variations in the western Mediterranean (e.g., the Tyrrhenian Sea), but smaller in the central and eastern Mediterranean Sea. In summer, the intraseasonal SST fluctuations are larger in almost the entire Mediterranean basin. Also summertime intraseasonal SST fluctuations are larger (up to three times near the Gulf of Lions) than their wintertime counterparts in the entire Mediterranean basin. The interannual SST variations are larger during summer in the western and central Mediterranean Sea and during winter in its eastern part. The leading empirical orthogonal functions (EOFs) of the Mediterranean SST and of the intensities of its intraseasonal fluctuations are characterized by the differing spatial-temporal structures both during winter and summer implying that their interannual variability is driven by different physical mechanisms. During winter, the EOF-1 of SST is associated with the East Atlantic teleconnection, whereas EOF-1 of the intensity of intraseasonal fluctuations is not linked significantly to regional atmospheric dynamics. The second EOFs of these variables are associated, respectively, with the East Atlantic/West Russia and the North Atlantic teleconnections. While during summer the atmospheric influence on Mediterranean SST is generally weaker, it is revealed that the EOF-1 of the intensity of intraseasonal SST fluctuations is linked to the Polar teleconnection.

  3. Mechanisms of land sea interactions the distribution of metals and sedimentary organic matter in sediments of a river-dominated Mediterranean karstic estuary

    NASA Astrophysics Data System (ADS)

    Sondi, Ivan; Lojen, Sonja; Juračić, Mladen; Prohić, Esad

    2008-10-01

    This paper examines disposal of metals and the origin, characteristics, and distribution of sedimentary organic matter (SOM) in a Mediterranean karstic estuary in the north-eastern Adriatic. This environment offers a real-time, small model system for studies of geochemical processes in microtidal Mediterranean estuaries that are infilling with sediments and classified as river-dominated disequilibrium estuaries. The results have shown that the longitudinal distribution of heavy metals in sediments follows the sedimentation dynamics and deposition pattern of river-borne, clay mineral particles. The highest concentration of metals was found in the restricted upper part of the estuary, characterized by rapid deposition of clay particles and terrestrial sedimentary organic matter, and decreases toward the open sea. The vertical distribution of metals in sediment cores depends on the prevailing pH and Eh conditions. Significant increases of the concentrations of metals in the uppermost strata are the result of recent anthropogenic inputs. The share of the terrestrial component in SOM, estimated by N/C org atomic ratios and δ 13C values, decreases with distance from the river mouth. The small vertical variation in δ 13C values of SOM indicates that a fast sedimentation rate overrides the diagenetically determined decomposition. The results obtained indicate that river-borne inorganic particles, natural terrigenous organic material, and anthropogenic metal loads are trapped in sediments of the estuarine system. Under the prevailing conditions, there is negligible transport towards the open sea.

  4. Foraminiferal record of anthropogenic environmental changes in the northeastern Adriatic Sea (Panzano Bay, Gulf of Trieste, Italy)

    NASA Astrophysics Data System (ADS)

    Vidovic, Jelena; Cosovic, Vlasta; Kern, Vieana; Gallmetzer, Ivo; Haselmair, Alexandra; Zuschin, Martin

    2016-04-01

    The northern Adriatic Sea is one of the world's largest modern epicontinental seas and a young marine ecosystem that has been subject to various natural and anthropogenic processes during the Holocene: marine transgression, regional climate fluctuations, urbanisation and pollution. The Gulf of Trieste, located in the northeastern part, presents the area of particular interest, as it is a shallow and sheltered embayment, prone to the accumulation of pollutants, populated for at least the last 2000 years and with recent anthropogenic pressure coming from several rivers, ports and industrial zones. The aim of this multidisciplinary study is to provide a high-resolution record of these processes using benthic foraminiferal assemblages, geochemical proxies (trace metals, nutrients and pollutants), sedimentological (sedimentation rates) and time-averaging data (from dated mollusc shells). One core of 1.5 m length was taken at the sampling station Panzano Bay, northernmost part of the Gulf of Trieste, at the water depth of 12.5 m. The sedimentation rate is estimated to be 2.5 mm/year, based on 210Pb sediment dating, while dating of the molluscs shells revealed the age at the bottom of the core to be approximately 500 years. The core was sliced into smaller subsamples, and four sediment fractions of each subsample (63, 125, 250 and 500 μm) were analysed for standard properties of the foraminiferal community (faunal composition, absolute and relative abundances of species, biodiversity indices), in order to make comparison with relevant physical and geochemical properties of the sediment. The results concerning changes in foraminiferal species composition, their abundance and biodiversity, supported by statistical analyses (cluster analysis, NMDS, PCA), allow identification of three major foraminiferal associations: 1) 80-150 cm - the oldest association is dominated by opportunistic genera ans species, characteristic for unstable environments: Valvulineria sp. (25

  5. Persistence of Pristine Deep-Sea Coral Gardens in the Mediterranean Sea (SW Sardinia)

    PubMed Central

    Bo, Marzia; Bavestrello, Giorgio; Angiolillo, Michela; Calcagnile, Lucio; Canese, Simonepietro; Cannas, Rita; Cau, Alessandro; D’Elia, Marisa; D’Oriano, Filippo; Follesa, Maria Cristina; Quarta, Gianluca; Cau, Angelo

    2015-01-01

    Leiopathes glaberrima is a tall arborescent black coral species structuring important facies of the deep-sea rocky bottoms of the Mediterranean Sea that are severely stifled by fishing activities. At present, however, no morphological in vivo description, ecological characterization, age dating and evaluation of the possible conservation actions have ever been made for any population of this species in the basin. A dense coral population was reported during two Remotely Operated Vehicle (ROV) surveys conducted on a rocky bank off the SW coasts of Sardinia (Western Mediterranean Sea). L. glaberrima forms up to 2 m-tall colonies with a maximal observed basal diameter of nearly 7 cm. The radiocarbon dating carried out on a colony from this site with a 4 cm basal diameter revealed an approximately age of 2000 years. Considering the size-frequency distribution of the colonies in the area it is possible to hypothesize the existence of other millennial specimens occupying a supposedly very stable ecosystem. The persistence of this ecosystem is likely guaranteed by the heterogeneous rocky substrate hosting the black coral population that represents a physical barrier against the mechanical impacts acted on the surrounding muddy areas, heavily exploited as trawling fishing grounds. This favorable condition, together with the existence of a nursery area for catsharks within the coral ramifications and the occurrence of a meadow of the now rare soft bottom alcyonacean Isidella elongata in small surviving muddy enclaves, indicates that this ecosystem have to be considered a pristine Mediterranean deep-sea coral sanctuary that would deserve special protection. PMID:25790333

  6. Persistence of pristine deep-sea coral gardens in the Mediterranean Sea (SW Sardinia).

    PubMed

    Bo, Marzia; Bavestrello, Giorgio; Angiolillo, Michela; Calcagnile, Lucio; Canese, Simonepietro; Cannas, Rita; Cau, Alessandro; D'Elia, Marisa; D'Oriano, Filippo; Follesa, Maria Cristina; Quarta, Gianluca; Cau, Angelo

    2015-01-01

    Leiopathes glaberrima is a tall arborescent black coral species structuring important facies of the deep-sea rocky bottoms of the Mediterranean Sea that are severely stifled by fishing activities. At present, however, no morphological in vivo description, ecological characterization, age dating and evaluation of the possible conservation actions have ever been made for any population of this species in the basin. A dense coral population was reported during two Remotely Operated Vehicle (ROV) surveys conducted on a rocky bank off the SW coasts of Sardinia (Western Mediterranean Sea). L. glaberrima forms up to 2 m-tall colonies with a maximal observed basal diameter of nearly 7 cm. The radiocarbon dating carried out on a colony from this site with a 4 cm basal diameter revealed an approximately age of 2000 years. Considering the size-frequency distribution of the colonies in the area it is possible to hypothesize the existence of other millennial specimens occupying a supposedly very stable ecosystem. The persistence of this ecosystem is likely guaranteed by the heterogeneous rocky substrate hosting the black coral population that represents a physical barrier against the mechanical impacts acted on the surrounding muddy areas, heavily exploited as trawling fishing grounds. This favorable condition, together with the existence of a nursery area for catsharks within the coral ramifications and the occurrence of a meadow of the now rare soft bottom alcyonacean Isidella elongata in small surviving muddy enclaves, indicates that this ecosystem have to be considered a pristine Mediterranean deep-sea coral sanctuary that would deserve special protection. PMID:25790333

  7. Discussion of the Ionian and Levantine Seas, NATO workshop on atmospheric and oceanic circulation in the Mediterranean Basin

    SciTech Connect

    Hopkins, T.S.

    1984-01-01

    The gross features and distinctiveness of its thermohaline circulation are described for the Ionian and Levantine Seas of the eastern Mediterranean. The paper also discusses the significance of the thermohaline coupling with neighboring Mediterranean basins. 22 refs. (ACR)

  8. First record of the Atlantic bumper Chloroscombrus chrysurus (Teleostei: Carangidae) in the Mediterranean Sea.

    PubMed

    Peña Rivas, L; Azzurro, E; Lloris, D

    2013-03-01

    In December 1997, one specimen of the Atlantic bumper, Chloroscombrus chrysurus was recorded for the first time in the Mediterranean Sea, off Almuñécar (Granada, Spain: 36° 43' 26″ N; 3° 41' 39″ W). This species probably entered the Mediterranean Sea via the Strait of Gibraltar. PMID:23464561

  9. Prognosis of Central-Eastern Mediterranean waterspouts

    NASA Astrophysics Data System (ADS)

    Keul, Alexander G.; Sioutas, Michalis V.; Szilagyi, Wade

    The North American waterspout forecasting methodology by Szilagyi is applied on a sample of 110 waterspout events for the years 2002-2006 over the Central-Eastern Mediterranean (the Adriatic, Ionian and Aegean Sea). First, the geographical distribution and frequency of the phenomena are shown. Four synoptic types of waterspout-prone circulation patterns are considered. For the Adriatic cases, five thermodynamic indices (KI, TT, SWEAT, CAPE, BRN) are used as possible predictors. The testing of the Szilagyi Waterspout Nomogram and Index (SWI), developed for the Great Lakes region, was favorable for the Mediterranean case data, validating its use as a prognostic tool. Results were presented and discussed at the 4th European Conference on Severe Storms ECSS at Trieste. Meteorologists should standardize and evaluate waterspout prognostic tools and implement a visual interface to improve the service for relevant user groups.

  10. Organic carbon dynamics in the Mediterranean Sea: An integrated study

    NASA Astrophysics Data System (ADS)

    Santinelli, Chiara; SempéRé, Richard; van Wambeke, France; Charriere, Bruno; Seritti, Alfredo

    2012-12-01

    Total (TOC) and dissolved (DOC) organic carbon vertical profiles were analyzed from 11 stations located in various regions of the Mediterranean Sea, together with the distribution of other physical, chemical and biological parameters. TOC showed the highest concentrations (68-83 μM) above the pycnocline, followed by a marked decrease to values of 45-48 μM at 100-200 m. Below 200 m, values of 40-45 μM were observed. The excess TOC and DOC occurring at each station was calculated by subtracting 48 μM from the observed concentrations. The stock of the excess TOC and DOC increased eastward; while surface DOC mineralization rates decreased from 1.5 μM d-1 to 0.26 μM d-1 eastward. The integrated average of the biological parameters in the above-pycnocline layer showed a bacterial production versus particulate primary production (BP/PPP) ratio ranging from 22% in the Ionian Sea (MIO station) to 31% in the Ligurian Sea (Dyfamed station), while bacterial carbon demand versus PPP was higher than 100%, considering a bacterial growth efficiency of both 15% and 30%. The data here reported indicate various scenarios of carbon dynamics. At the stations west of the Sardinian Channel, the microbial loop was very active, and a high flux of carbon to the microbial loop (large bacterial and protist abundance) may be hypothesized, which would result in a low DOC concentration. At the stations east of the Sardinian Channel, no significant longitudinal variation was found in DOC and BP. DOC accumulated at these stations, possibly due to bacteria P-limitation, to DOC chemical composition and/or to the occurrence of different prokaryotic populations with a different ability to consume the available DOC.

  11. Projected future wave climate in the NW Mediterranean Sea

    NASA Astrophysics Data System (ADS)

    Casas-Prat, M.; Sierra, J. P.

    2013-07-01

    Projected future regional wave climate scenarios at a high temporal-spatial scale were obtained for the NW Mediterranean Sea, using five combinations of regional-global circulation models. Changes in wave variables were analyzed and related to the variations of the forcing wind projections, while also evaluating the evolution of the presence of the different types of sea states. To assess the significance of the changes produced, a bootstrap-based method was proposed, which accounts for the autocorrelation of data and correctly reproduces the extremes. For the mean climate, relative changes of Hs up to ±10% were obtained, whereas they were around ±20% for the extreme climate. In mean terms, variations of Hs are similar to those associated with wind speed but are enhanced/attenuated, respectively, when fetch conditions are favorable/unfavorable. In general, most notable alterations are not in the Hs magnitude but rather in its direction. In this regard, during the winter season, it is interesting to note that the significant deviations between the results derived from the two global circulation models are larger than those between regional models. ECHAM5 simulated an enhanced west wind flow that is translated into more frequent W-NW waves, whereas the HadCM3Q3 global model gives rise to the east component, which contributes to a higher intensity and number of storms coming from such a direction and directly affects the wind-sea/swell distribution of coastal stretches that face east, like the Catalan coast. Different patterns of change were obtained during the summer when a common rise of NE-E waves was found.

  12. New data on the Holocenic sea-level rise in NW Sicily (Central Mediterranean Sea)

    NASA Astrophysics Data System (ADS)

    Antonioli, F.; Cremona, G.; Immordino, F.; Puglisi, C.; Romagnoli, C.; Silenzi, S.; Valpreda, E.; Verrubbi, V.

    2002-09-01

    The emerged and submerged coastal tracts of selected areas in NW Sicily (San Vito Lo Capo Promontory and Marettimo Island in the Egadi Archipelago) have been studied by means of an interdisciplinary approach (geomorphological and neotectonic surveys, palaeontological, depositional and petrographical observations) with the aim to characterize the coastal evolution of the sector over a wide time frame (Late Pleistocene and Holocene) and to recognize the geological indicators of relative sea-level fluctuations. Neotectonic studies performed all along the coastal sector through the check of the present-day height of marine notches and of the inner margin of marine terraces of Eutyrrhenian age allowed to assess the entity of post-Tyrrhenian differential crustal movements in the area. The calculated rates of uplift confirm the relative stability of the area in the last 125 ka and that the relative corrections introduced can be considered negligible in the reconstruction of sea-level rise in the last thousand years. On the base of these considerations, the sea-level rise curve which has been drawn for the Holocene through the radiometric dating ( 14C and U/Th) of submerged speleothems and Vermetid reefs is assumed to gain a regional significance and to represent a good reference datum for the Central-Southern Mediterranean Sea. In addition, the sea-level rise data are in good agreement with the predicted sea-level curves based on geophysical models previously applied to the same study areas.

  13. Reanalysis of biogeochemical properties in the Mediterranean Sea

    NASA Astrophysics Data System (ADS)

    Cossarini, Gianpiero; Teruzzi, Anna; Salon, Stefano; Solidoro, Cosimo

    2014-05-01

    In the 3D variational (3DVAR) assimilation approach the error covariance matrix can be decomposed in a series of operators. The decomposition makes the 3DVAR particularly suitable for marine biogeochemistry data assimilation, because of the reduced computational costs of the method and its modularity, which allows to define the covariance among the biogeochemical variables in a specific operator. In the present work, the results of 3DVAR assimilation of surface chlorophyll concentration in a multi-annual simulation of the Mediterranean Sea biogeochemistry are presented. The assimilated chlorophyll concentrations are obtained from satellite observations (Volpe et al. 2012). The multi-annual simulation is carried out using the OPATM-BFM model (Lazzari et al. 2012), which describes the low trophic web dynamics and is offline coupled with the MFS physical model (Oddo et al. 2009). In the OPATM-BFM four types of phytoplankton are simulated in terms of their content in carbon, nitrogen, phosphorous, silicon and chlorophyll. In the 3DVAR the error covariance matrix has been decomposed in three different operators, which account for the vertical, the horizontal and the biogeochemical covariance (Teruzzi et al. 2014). The biogeochemical operator propagates the result of the assimilation to the OPATM-BFM variables, providing innovation for the components of the four phytoplankton types. The biogeochemical covariance has been designed supposing that the assimilation preserves the physiological status and the relative abundances of phytoplankton types. Practically, the assimilation preserves the internal quotas of the components for each phytoplankton as long as the optimal growth rate condition are maintained. The quotas preservation is not applied when the phytoplankton is in severe declining growth phase, and the correction provided by the assimilation is set equal to zero. Moreover, the relative abundances among the phytoplankton functional types are preserved. The 3DVAR

  14. Primary and Secondary Aerosol Investigation from Different Sea-Waters in the Mediterranean Sea

    NASA Astrophysics Data System (ADS)

    D'anna, B.; Marchand, N.; Sellegri, K.; Sempéré, R.; Mas, S.; George, C.; Meme, A.; Frihi, A.; Pey, J.; Schwier, A.; Delmont, A.

    2014-12-01

    The Mediterranean Sea is a special marine environment characterized by low biological activity and high anthropogenic pressure. It is often difficult to discriminate the contribution of Primary and Secondary Aerosol formed at the sea-air interface from background level of the aerosol. We therefore decided to study the sea-air exchanges in a controlled environment provided by a 2m3simulation chamber, using freshly collected sea-water samples from the SEMEX site (43°15'64 N, 05°20'01 E) near Marseille bay. Two types of experiments were conducted for 4 weeks testing 3 different sea-waters. Primary sea-aerosol was generated by bubble-bursting method, then introduced in the simulation chamber and exposed to atmospheric oxidants (O3, OH) and light to simulated primary aerosol aging. A second set of experiments focused on secondary particle formation upon illumination and/or ozone exposure of the sea-water surface (15l of sea-water were deposited in a pyrex container located inside the simulation chamber). New particle formation was only observed for relatively high DOC level of the sea-water sample. Particles detection and analysis was followed by a PSM (1nm size), a CPC (2.5nm size), a SMPS (granulometry), a CCN chamber for hygroscopicity studies, a TOF-AMS (Aerodyne) for chemical analysis of the sub-micrometer fraction. Off-line analysis included TEM-EDX samples for morphology and size distribution studies and a hybrid quadrupole-orbitrap mass spectrometer (Thermo Fischer) for the molecular identification of the organic fraction. VOCs were measured on-line by PTR-HR-MS. The seawater samples were filtered at 60μm before use and were daily analyzed for chemical (colored dissolved organic matter, particulate matter and related polar compounds, transparent polysaccharides and nutrients concentration) and biological (chlorophyll a, virus, phytoplankton and zooplankton) analyses.

  15. The Mediterranean Sea 1985-2007 re-analysis: validation results

    NASA Astrophysics Data System (ADS)

    Adani, Mario; Dobricic, Srdjan; Pinardi, Nadia

    2010-05-01

    . The Mean Dynamic Topography of (Dobricic, 2005) has been used for both experiments. The model is forced with a combined dataset of ECMWF analysis when available and ERA-15. The precipitations are monthly mean climatology of the NCEP re-analysis (Kistler et.al 2001), the river runoff data are monthly mean climatology from the Global Runoff Data Centre (GRDC) and from Raicic (1996) for the minor Adriatic Sea rivers. The assimilation schemes help in reducing the spin up time of the model by acting as a forcing inside the water column. Both re-analyses show significantly better results then the simulation reducing both bias and root mean square error even though the structure of the error remains almost the same of the simulation: the largest error for tracers is confined in the thermocline especially in summer, highlighting a problem in the mixing parameterization; the majors error for SLA is confined in the most dynamically active areas. Satellite altimetry observations result in a fundamental dataset to constrain model solution and since its homogeneity in the sampling they permits a consistent assessment of the model behaviour along the years which it is not possible from in-situ observations whose sampling is extremely inhomogeneous both in time and space. This study describes the development of modelling and data assimilation tools for the production of re-analysis for the entire Mediterranean Sea. In order to carry out a re-analysis two major steps were undertaken in this work. In the first, the general circulation model was upgraded to have the correct air-sea water fluxes. In the second, two assimilation schemes, one new and the other consolidated, were compared to show their impact on the quality of the re-analysis. The general circulation model used in this study is shown to be capable of reproducing quite accurately the ocean dynamics of the Mediterranean Sea. The results have shown that the model solution is in agreement with data and observations, even

  16. Mercury in the sediments of the Marano and Grado Lagoon (northern Adriatic Sea): Sources, distribution and speciation

    NASA Astrophysics Data System (ADS)

    Acquavita, Alessandro; Covelli, Stefano; Emili, Andrea; Berto, Daniela; Faganeli, Jadran; Giani, Michele; Horvat, Milena; Koron, Neža; Rampazzo, Federico

    2012-11-01

    The existence of mining tailings in Idrija (Slovenia) and their subsequent transportation via the Isonzo River has been the primary source of mercury (Hg) in the northern Adriatic Sea for almost 500 years, making the Gulf of Trieste and the adjacent Marano and Grado Lagoon two of the most contaminated marine areas in the world. A further, more recent, contribution of Hg has been added by the operation of a chlor-alkali plant (CAP) located in the drainage basin flowing into the Lagoon. On the basis of previous research, as well as new data obtained from the "MIRACLE" project (Mercury Interdisciplinary Research for Appropriate Clam farming in a Lagoon Environment), the spatial distribution of Hg and its relationships with methylmercury (MeHg), organic matter and several geochemical parameters in surface sediments were investigated. The predominant and long-term impacts of the cinnabar-rich Isonzo River particulate matter in the Lagoon surface sediments are evident and confirmed by a decreasing concentration gradient from east (>11 μg g-1) to west (0.7 μg g-1). Hg originated from the CAP is only significant in the central sector of the Lagoon. Hg is primarily associated with fine-grained sediments (<16 μm), as a consequence of transport and dispersion from the fluvial source through littoral and tidal currents. However, speciation analyses highlighted the presence of Hg sulphides in the coarse sandy fraction of sediments from the eastern area, as expected given the origin of the sedimentary material. Unlike Hg, the distribution of MeHg (0.47-7.85 ng g-1) does not show a clear trend. MeHg constitutes, on average, 0.08% of total Hg and percentages are comparable to those obtained in similar lagoon environments. Higher MeHg concentrations in low to intermediate Hg-contaminated sediments indicate that the metal availability is not a limiting factor for MeHg occurrence, thus suggesting a major role played by environmental conditions and/or speciation. The reasonably

  17. Black Sea and Mediterranean Sea interaction: influence of the North Aegean dynamics

    NASA Astrophysics Data System (ADS)

    Androulidakis, Yannis; Krestenitis, Yannis; Kourafalou, Vassiliki

    2013-04-01

    The brackish Black Sea Waters outflow to the Aegean Sea, through the Dardanelles Straits, affects and determines significantly the hydrodynamic and physical characteristics of the Aegean Sea. At the same time, it affects several biological parameters, like chl-a concentrations, and, therefore, the general quality of the marine environment. The investigation and mathematical simulation of the North Aegean's physical oceanography contributes to the knowledge and understanding of the buoyant waters' circulation initial conditions in the wider East Mediterranean region. The implementation and adaptation of the 3-d hydrodynamic mathematical model HYCOM (Hybrid Coordinate Ocean Model) in the North Aegean Sea (1/50οx1/50o), significantly contributes to the investigation of the area's hydrodynamic circulation. HYCOM, due to its hybrid coordinate operation, can describe at a satisfactory level, all the different topography and mixing cases of the complicated N. Aegean region. In addition, the high resolution atmospheric forcing and the nesting with a data assimilated broader Mediterranean HYCOM model along the southern open boundary of the North Aegean model, benefit the quality of the results and constitutes an important tool on the description and understanding of the Black Sea influence to the region's dynamics. A fundamental objective is the application and comparison of different Dardanelles outflow parameterizations based a) on the Black Sea water budget, b) on current measurements from a telemetric station in Limnos Island, and c) on historical time series. The Black Sea Waters plume evolution and the circulation patterns are dependant on the outflow rate magnitude, the flow distribution inside the straits and the prevailing winds. The long-term simulation covers the period of the last 20 years (1990-2010), investigating several physical characteristics of the North Aegean Sea, such as the deep water masses evolution, the major Black Sea waters circulation patterns

  18. Historical trends (1998-2012) of nickel (Ni), copper (Cu) and chromium (Cr) concentrations in marine sediments at four locations in the Northern Adriatic Sea.

    PubMed

    Traven, Luka; Furlan, Nikolina; Cenov, Arijana

    2015-09-15

    Historical trends (1998-2012) nickel (Ni), copper (Cu) and chromium (Cr) concentrations in marine sediments were assessed at four locations in the Northern Adriatic Sea (Croatia) in the proximity of an oil refinery. Ecological risks were characterized by benchmarking the dataset against Sediment Quality Guidelines (SQG). A significant number of samples had Ni values above ERL with no exceedance of the ERL values for Cu and Cr. Weak positive historical trends were found for only for Cu. At all sites there were statistically significant correlations between Ni and Cr indicating a common origin of these heavy metals in the investigated marine sediments. There were statistically significant differences between the sites under the direct influence of the oil refinery compared to the control site indicating the possibility that the oil refinery is contributing to the concentration of these heavy metals in the marine sediments. PMID:26146134

  19. On the occurrence of the fireworm Eurythoe complanata complex (Annelida, Amphinomidae) in the Mediterranean Sea with an updated revision of the alien Mediterranean amphinomids

    PubMed Central

    Arias, Andrés; Barroso, Rômulo; Anadón, Nuria; Paiva, Paulo C.

    2013-01-01

    Abstract The presence of two species within the Eurythoe complanata complex in the Mediterranean Sea is reported, as well as their geographical distributions. One species, Eurythoe laevisetis, occurs in the eastern and central Mediterranean, likely constituting the first historical introduction to the Mediterranean Sea and the other, Eurythoe complanata, in both eastern and Levantine basins. Brief notes on their taxonomy are also provided and their potential pathways for introduction to the Mediterranean are discussed. A simplified key to the Mediterranean amphinomid genera and species of Eurythoe and Linopherus is presented plus an updated revision of the alien amphinomid species reported previously from the Mediterranean Sea. A total of five exotic species have been included; information on their location, habitat, date of introduction and other relevant features is also provided. PMID:24146576

  20. Long-term ecological changes in the north Adriatic Sea: Epi-to Infauna turnover at the Brijuni islands national park

    NASA Astrophysics Data System (ADS)

    Pifeas, Iason; Gallmetzer, Ivo; Haselmair, Alexandra; Stachowitsch, Michael; Zuschin, Martin

    2015-04-01

    The northern Adriatic Sea with its densely populated coastline experienced strong anthropogenic impacts during the last centuries. The Brijuni islands at the southern tip of Istria, Croatia, are a national park since 1983 and represent a study area of special interest when comparing impacted marine areas with regions under relatively long-term protection that were able to recover from the pressure of fishing and bottom trawling. The present study is part of a project on the historical ecology of the northern Adriatic sea and focusses on long-term ecological changes and benthic community shifts as a result of anthropogenic impacts since the Holocene transgression. Several cores of 1.5 m length and a diameter of 90 mm were taken close to the main island of Brijuni and sliced into smaller subunits for sediment analyses and the investigation of death assemblages. Hard part remains of molluscs, crustaceans, bryozoans, echinoderms and sedentary polychaetes were analysed for species composition, abundance and indicators for high biomass epifauna. Death assemblages were compared with surface samples of the recent fauna taken at the same area by grab-sampling and by divers using a 100 x 100 cm frame. Data analyses revealed a steep increase of species abundance and diversity in the early stages of the Holocene transgression, at the very bottom of the core, followed by a steady decline, representing a major shift from a previously epibenthic to an infauna dominated community. Towards the top of the core, this trend weakens, and in the uppermost 6 cm it even reverses indicating a possible recovery of the benthic communities since the protection of the area. By correlating down-core changes in benthic community structure with sediment parameters (grain size distribution, TOC, heavy metal content, concentrations of organic pollutants) and data from radiometric sediment dating, we can further improve our understanding of the timing and the magnitude of past ecological changes and

  1. Rising Mediterranean Sea Surface Temperatures Amplify Extreme Summer Precipitation in Central Europe

    PubMed Central

    Volosciuk, Claudia; Maraun, Douglas; Semenov, Vladimir A.; Tilinina, Natalia; Gulev, Sergey K.; Latif, Mojib

    2016-01-01

    The beginning of the 21st century was marked by a number of severe summer floods in Central Europe associated with extreme precipitation (e.g., Elbe 2002, Oder 2010 and Danube 2013). Extratropical storms, known as Vb-cyclones, cause summer extreme precipitation events over Central Europe and can thus lead to such floodings. Vb-cyclones develop over the Mediterranean Sea, which itself strongly warmed during recent decades. Here we investigate the influence of increased Mediterranean Sea surface temperature (SST) on extreme precipitation events in Central Europe. To this end, we carry out atmosphere model simulations forced by average Mediterranean SSTs during 1970–1999 and 2000–2012. Extreme precipitation events occurring on average every 20 summers in the warmer-SST-simulation (2000–2012) amplify along the Vb-cyclone track compared to those in the colder-SST-simulation (1970–1999), on average by 17% in Central Europe. The largest increase is located southeast of maximum precipitation for both simulated heavy events and historical Vb-events. The responsible physical mechanism is increased evaporation from and enhanced atmospheric moisture content over the Mediterranean Sea. The excess in precipitable water is transported from the Mediterranean Sea to Central Europe causing stronger precipitation extremes over that region. Our findings suggest that Mediterranean Sea surface warming amplifies Central European precipitation extremes. PMID:27573802

  2. Rising Mediterranean Sea Surface Temperatures Amplify Extreme Summer Precipitation in Central Europe.

    PubMed

    Volosciuk, Claudia; Maraun, Douglas; Semenov, Vladimir A; Tilinina, Natalia; Gulev, Sergey K; Latif, Mojib

    2016-01-01

    The beginning of the 21st century was marked by a number of severe summer floods in Central Europe associated with extreme precipitation (e.g., Elbe 2002, Oder 2010 and Danube 2013). Extratropical storms, known as Vb-cyclones, cause summer extreme precipitation events over Central Europe and can thus lead to such floodings. Vb-cyclones develop over the Mediterranean Sea, which itself strongly warmed during recent decades. Here we investigate the influence of increased Mediterranean Sea surface temperature (SST) on extreme precipitation events in Central Europe. To this end, we carry out atmosphere model simulations forced by average Mediterranean SSTs during 1970-1999 and 2000-2012. Extreme precipitation events occurring on average every 20 summers in the warmer-SST-simulation (2000-2012) amplify along the Vb-cyclone track compared to those in the colder-SST-simulation (1970-1999), on average by 17% in Central Europe. The largest increase is located southeast of maximum precipitation for both simulated heavy events and historical Vb-events. The responsible physical mechanism is increased evaporation from and enhanced atmospheric moisture content over the Mediterranean Sea. The excess in precipitable water is transported from the Mediterranean Sea to Central Europe causing stronger precipitation extremes over that region. Our findings suggest that Mediterranean Sea surface warming amplifies Central European precipitation extremes. PMID:27573802

  3. Plankton in the open Mediterranean Sea: a review

    NASA Astrophysics Data System (ADS)

    Siokou-Frangou, I.; Christaki, U.; Mazzocchi, M. G.; Montresor, M.; Ribera D'Alcalá, M.; Vaqué, D.; Zingone, A.

    2009-11-01

    We present an overview of the plankton studies conducted during the last 25 years in the epipelagic offshore waters of the Mediterranean Sea. This quasi-enclosed sea is characterized by a rich and complex physical dynamics that includes unique thermohaline features, particular multilayer circulation, topographic gyres, and meso- and sub-mesoscale activity. Recent investigations have basically confirmed the long-recognised oligotrophic character of this sea, which enhances along both the west-east, and the north-south directions. Nutrient availability is low, especially for phosphorous (N:P up to 60), although limitation may be relaxed by inputs from highly populated coasts and from the atmosphere. Phytoplankton biomass as chl-a, generally displays low values (less than 0.2 μg chl-a l-1) over large areas, with a modest late winter increase. A large bloom (up to 3 μg l-1) throughout the late winter and early spring is only observed in the NW area. Relatively high biomass peaks are also recorded in fronts and cyclonic gyres. A deep chlorophyll maximum is a~permanent feature for the whole basin (except during the late winter mixing). It progressively deepens from the Alboran Sea (30 m) to the easternmost Levantine basin (120 m). Primary production reveals a similar west-east decreasing trend and ranges from 59 to 150 g C m-2 y-1 (in situ measurements). Overall the basin is largely dominated by small-sized autotrophs, microheterotrophs and egg-carrying copepod species. The phytoplankton, the microbial (both autotrophic and heterotrophic) and the zooplankton components reveal a considerable diversity and variability over spatial and temporal scales, the latter less explored though. Examples are the wide diversity of dinoflagellates and coccolithophores, the multifarious role of diatoms or picoeukaryotes, and the distinct seasonal or spatial patterns of the species-reach copepod genera or families which dominate in the basin. Major dissimilarities between western and

  4. The response of the lower ionosphere driven by the chain of the meteotsunamis in the Mediterranean Sea during 23 - 28 June 2014

    NASA Astrophysics Data System (ADS)

    Solovieva, Maria; Rozhnoi, Alexander; Levin, Boris; Biagi, Pier Francesco; Maggipinto, Tommaso; Fedun, Viktor

    2016-04-01

    The tsunamis are long waves originated in the seas and oceans from different reasons. The basic contribution to tsunami formation is created by the earthquakes, however there are another sources of the tsunamis. Among them some part of the tsunamis are formed due to the meteorological reasons. Such tsunamis formed under the influence of atmospheric processes are named the meteotsunamis. Jumps of the atmospheric pressure, typhoons, hurricanes, storms, cold fronts, etc. can be the meteotsunamis reasons. The meteotsunamis are observed at many locations around the world: in oceans, seas and even lakes. Tsunamis and meteotsunamis have the same periods, same spatial scales and they also generate internal gravity waves (IGWs) propagating upward into the ionosphere where they dissipate and produce perturbations in the plasma density. These perturbations can be detected by electromagnetic waves such as sub-ionospheric very low and low-frequencies (VLF/LF) signals. A chain of meteotsunamis was observed in the Mediterranean and the Black Sea during 23 - 28 June 2014. These events were caused by a unique synoptic system that traveled above the Mediterranean Sea from Spain to Turkey and into the Black Sea. The system produced sharp atmospheric pressure changes (more than 2 hPa in 5 min), which caused tsunami waves in the open waters of 2-3 cm. The waves traveled in the open sea in different directions and intensified topographically close to the coast. The measurements from the VLF/LF ground based network of receiver stations in the South Europe "The International Network For Frontier Research on Earthquake Precursors" (INFREP) were used to study the response of the lower ionosphere to the meteotsunamis in the Mediterranean Sea. Revealed VLF/LF anomalies coincided in time with meteotsunami events. The nighttime anomalies in low-frequency signal were observed on 23-24 June in the region between Spain and Sicily. The next VLF/LF anomalies were registered on 25-26 June near Italy

  5. Seasonal cycle of suspended barite in the mediterranean sea

    NASA Astrophysics Data System (ADS)

    Sternberg, E.; Jeandel, C.; Robin, E.; Souhaut, M.

    2008-08-01

    Biogenic barium (Ba xs) was measured in suspended particles at the DYFAMED site in the northwestern Mediterranean Sea, on a monthly basis between February and June 2003. The barium content of barite (BaSO 4) micro-crystals was investigated using Scanning Electron Microscopy (SEM). Suspended particles were collected by filtration of small volumes of seawater (˜10 L), as well as large volumes up to 2400 L in March and in May. The Ba xs profiles obtained from small-volume filtration display the typical mesopelagic maximum reported by earlier studies at ˜200 m depth, with concentrations up to 595 pmol L -1. In addition, suspended Ba xs was found almost exclusively in the form of micro-crystalline barite, except in February. The Ba xs profiles obtained from large-volume filtration are consistent with the small-volume filtration findings, but reveal a significant Ba xs peak of 1698 pmol L -1 in the surface waters in May. Seasonal sampling at the DYFAMED site shows a net increase in barite concentration during phytoplanktonic blooms, confirming the involvement of biological systems in barite formation, as well as the potential role of barite as a primary productivity tracer. In addition, the coincidence between the mesopelagic barite maximum and the oxygen minimum layer suggests that barite is primarily found at depths of intense remineralization, in agreement with the hypothesis that barite forms within microenvironments of decaying organic matter.

  6. Airborne and vapor phase hydrocarbons over the Mediterranean Sea

    SciTech Connect

    Marie-Alexandrine, S.; Jean-Claude, M.; Anne, L.; Alain, S.

    1990-11-01

    n-Alkane distributions and concentrations have been determined in the atmospheric particulate and gas phases for samples collected over the Mediterranean Sea. Distributions of airborne alkanes exhibited a strong odd to even predominance in the C{sub 22}-C{sub 38} range associated with the presence of unresolved compounds indicating a mixture of terrigenous and anthropogenic inputs. Variations in their concentration levels could be related to the origin of air masses. Solvent extractable gas phase n-alkanes dominated in the C{sub 15}-C{sub 22} range with a slight predominance of n-C{sub 17} except in one sample were C{sub 18} and C{sub 20} were dominant. A hump of unresolved compounds shifted toward low molecular weight was observed in all the samples. The origin of vapor phase hydrocarbons is discussed with respect to the composition of seawater samples collected during the same cruise. From lifetime and transport time considerations as well as distribution features, both marine and continental origins, as distribution features, both marine and continental origins, likely anthropogenic, are suggested. The strong terrigenous signal of the suspended particles in the microlayer and underlying waters is attributed to aerosol deposition. The dissolved alkane compositional feature suggested both marine and anthropogenic sources.

  7. Results on SSH neural network forecasting in the Mediterranean Sea

    NASA Astrophysics Data System (ADS)

    Rixen, Michel; Beckers, Jean-Marie; Alvarez, Alberto; Tintore, Joaquim

    2002-01-01

    Nowadays, satellites are the only monitoring systems that cover almost continuously all possible ocean areas and are now an essential part of operational oceanography. A novel approach based on artificial intelligence (AI) concepts, exploits pasts time series of satellite images to infer near future ocean conditions at the surface by neural networks and genetic algorithms. The size of the AI problem is drastically reduced by splitting the spatio-temporal variability contained in the remote sensing data by using empirical orthogonal function (EOF) decomposition. The problem of forecasting the dynamics of a 2D surface field can thus be reduced by selecting the most relevant empirical modes, and non-linear time series predictors are then applied on the amplitudes only. In the present case study, we use altimetric maps of the Mediterranean Sea, combining TOPEX-POSEIDON and ERS-1/2 data for the period 1992 to 1997. The learning procedure is applied to each mode individually. The final forecast is then reconstructed form the EOFs and the forecasted amplitudes and compared to the real observed field for validation of the method.

  8. Retrieval of eddy dynamics from SMOS sea surface salinity measurements in the Algerian Basin (Mediterranean Sea)

    NASA Astrophysics Data System (ADS)

    Isern-Fontanet, Jordi; Olmedo, Estrella; Turiel, Antonio; Ballabrera-Poy, Joaquim; García-Ladona, Emilio

    2016-06-01

    The circulation in the Algerian Basin is characterized by the presence of fresh-core eddies that propagate along the coast or at distances between 100 and 200 km from the coast. Enhancements in the processing of the Soil Moisture and Ocean Salinity (SMOS) data have allowed to produce, for the first time, satellite sea surface salinity (SSS) maps in the Mediterranean Sea that capture the signature of Algerian eddies. SMOS data can be used to track them for long periods of time, especially during winter. SMOS SSS maps are well correlated with in situ measurements although the former has a smaller dynamical range. Despite this limitation, SMOS SSS maps capture the key dynamics of Algerian eddies allowing to retrieve velocities from SSS with the correct sign of vorticity.

  9. Organophosphate ester (OPE) flame retardants and plasticizers in the open Mediterranean and Black Seas atmosphere.

    PubMed

    Castro-Jiménez, Javier; Berrojalbiz, Naiara; Pizarro, Mariana; Dachs, Jordi

    2014-03-18

    The presence of organophosphate ester (OPE) flame retardants and plasticizers has been confirmed for the first time in the atmosphere over the Mediterranean and Black Seas. Atmospheric aerosol samples were collected during two West-East oceanographic cruises across the Mediterranean and in the southwest Black Sea. This comprehensive assessment of baseline concentrations of aerosol phase OPEs, spatial distribution, and related deposition fluxes reveals levels ranging from 0.4 to 6.0 ng m(-3) for the ∑14OPEs and a lack of significant differences among sub-basins. Levels measured across the Mediterranean Sea and in the Black Sea are in the upper range or higher than those from previous reports for the marine atmosphere, presumably due to proximity to sources. From 13 to 260 tons of OPEs are estimated to be annually loaded to the Mediterranean Sea open waters from the atmosphere. Tris-(1-chloro-2-propyl)phosphate (TCPP) was the most abundant compound over the atmosphere of all the Mediterranean and Black Sea sub-basins, and therefore the chemical reaching surface waters at a higher extent by dry deposition. The atmospheric deposition fluxes of phosphorus due to OPE deposition is a significant fraction of known atmospheric inputs of new organic phosphorus (P), suggesting the relevant role that anthropogenic organic pollutants could play in the P cycle. PMID:24564832

  10. Tsunami Propagation Database for the Mediterranean and Aegean Seas

    NASA Astrophysics Data System (ADS)

    Kanoglu, U.; Hoto, O.; Kalligeris, N.; Flouri, E.; Aydin, B.; Moore, C. W.; Synolakis, C. E.

    2012-12-01

    Pre-computed tsunami scenario databases are common tools to develop long- or short-term forecasting methodologies and hazard assessment approaches for tsunami-prone regions worldwide. The benefits of such databases include the possibility of probabilistic studies (Gonzalez et al., 2009, J. Geophys. Res. 114, Article Number: C11023), inundation mapping (Barberopoulou et al., 2011, Pure Appl. Geophys. 168(11), 2133-2146), or real-time forecasting (Wei et al., 2008, Geophys. Res. Lett. 35(4), Article Number: L04609). As a result, several tsunami propagation databases have been developed including one by NOAA's Pacific Marine Environmental Laboratory (PMEL), and another by the Australian Bureau of Meteorology (BOM). Pre-computed tsunami scenario databases utilize different approaches. PMEL's tsunami propagation database is based on the concept of a pre-computed tsunami scenarios consisting of propagation results from 100km x 50km fault planes with a slip value of 1m referred to as tsunami source functions. PMEL's source functions are placed along the subduction zones in several rows, covering known faults throughout the major ocean basins. Linearity of the tsunami propagation in the open ocean allows scaling and/or combination of the pre-computed tsunami source functions to generate a desired scenario. The BOM database considers five earthquakes with magnitudes changing from 7.0 to 9.0 at each location with 100km intervals along the subduction zone. However, to date, no similar approach has been computed along the subduction zones in the Aegean and Mediterranean Seas, even though, historically, there have been a considerable number of tsunami events which caused damage in the region (Ambraseys and Synolakis, 2010, J. Earthquake Eng. 14 (3), 309-330, Article Number: PII 919600673). A new project was initiated between Greece and Turkey supported by General Secretariat for Research & Technology, The Ministry for Development (GSRT) of Greece and The Scientific and

  11. Comparison of sea surface winds derived from active and passive microwaves instruments on the Mediterranean Sea

    NASA Astrophysics Data System (ADS)

    De Biasio, Francesco; Zecchetto, Stefano

    2013-04-01

    In order to characterize the energy and momentum fluxes at the air-sea interface, the surface wind vector must be known with adequate spatial and temporal coverages. Satellite-borne active and passive microwaves instruments perform such measurements. In the Mediterranean Sea, and in general in enclosed or semi-enclosed basins, an adequate coverage is yet more difficult to achieve than in open sea, because of the presence of vast coastal areas and elevated orography near the coastline. This study aims to compare the performance of three of such instruments (two actives and one passive) over several years of activity over the Mediterranean Sea, in order to delve into the possibility of using the three data-sets as a common reference for marine meteorology investigations, dramatically improving the availability of surface wind data in the Mediterranean Sea. They are the METOP-A ASCAT scatterometer, the QuikSCAT SeaWinds scatterometer and the Coriolis WindSat radiometer. ASCAT and QuikSCAT data are freely available for download, at spatial resolution of 25 km by 25 km and 12.5 km by 12.5 km, from the Physical Oceanography Distributed Active Archive Center PO.DAAC (http://podaac.jpl.nasa.gov). ASCAT near real time data have 2 hours latency. The time span covered by these data is March 2007-present for ASCAT, July 1999-November 2009 for QuikSCAT. In the Mediterranean Sea the nominal temporal coverage is less then 2 hit per point per day for both. WindSat data have spatial resolution of 25 km by 25 km, cover the period February 2003-present, and are freely available for download from Remote Sensing Systems (http://www.ssmi.com). They are available as delayed datasets covering one day at a time. The two collocated datasets cover the period February 2003 - November 2009 (WindSat - QuikSCAT) and March 2009 - November 2010 (WindSat - ASCAT), and offer the means to perform: - a comparison of the performances of active and passive microwaves instruments; - a very long

  12. Vertical distribution of marine cyanobacteria Synechococcus spp. in the Black, Marmara, Aegean, and eastern Mediterranean seas

    NASA Astrophysics Data System (ADS)

    Uysal, Zahit

    2006-08-01

    The vertical distributions of the unicellular cyanobacteria Synechococcus were studied in several highly contrasting seas: the Black Sea, Sea of Marmara, Aegean Sea, and Mediterranean Sea. Cell abundances varied significantly on both vertical and horizontal scales in all physically and spatially discrete water masses. Epifluorescence microscope cell counts from all seas clearly showed that majority of the population remains suspended in the surface-mixed layer and decreases gradually towards the base of the euphotic zone. Surface spatial distributions in the Black Sea were heterogeneous. Salinity, rather than temperature, seemed to have the greatest impact on the surface distribution of cells in this highly eutrophic sea. Changes in abundance in the mixed layer were small compared to the abrupt changes below the halocline, especially in the Black Sea and the Sea of Marmara. In contrast to the Black Sea, the major population remains suspended above the depth of fluorescence maximum in the Aegean and eastern Mediterranean seas. Significant correlations ( r>P0.01) were observed between cell counts and physical and chemical parameters with depth in the Black Sea. In all seas, cells at subsurface chlorophyll- a maximum layer (SCML) reflected brighter and longer fluorescence than those present at the surface and below. Cell size derived from flow cytometry indicated the presence of larger cells at the surface mixed layer compared to those at depth.

  13. Factors favouring phytoplankton blooms in the northern Adriatic: towards the northern Adriatic empirical ecological model

    NASA Astrophysics Data System (ADS)

    Kraus, R.; Supić, N.; Precali, R.

    2016-01-01

    Influenced by one of the largest Mediterranean rivers, Po, the northern Adriatic (NA) production is highly variable seasonally and interannually. The changes are especially pronounced between winters and seemingly reflect on total Adriatic bioproduction of certain species (anchovy). We analysed the long-term changes in the phytoplankton production in the region, as derived from monthly oceanographic cruises, in relation to concomitant geostrophic currents distribution in the area and to Po River discharge rates in days preceding the cruises. In winter and early spring the phytoplankton abundances depended on existing circulation fields, in summer and autumn they were related to Po River discharge rates 1-15 days earlier and on concomitant circulation fields, while in late spring phytoplankton abundances increased 1-3 days after high Po River discharge rates regardless of the circulation fields. During the entire year the phytoplankton abundances were dependent on forcing of the previous 1-12 months of surface fluxes and/or Po River rates. The role of wind was uncertain but that was partly due to unmatched sampling time frames between meteorological and sea data. Low evaporation rates in November reflected significantly on the next February circulation pattern and, although with somewhat lower significance, on large phytoplankton blooms in the same month. We showed that the role of wind in evaporative flux enhancements is not straightforward as evaporative fluxes are highly dependent on other factors, e.g. air-sea temperature difference. Wind-induced vertical mixing was only sporadically related to phytoplankton abundances. From 1990 to 2004 a shift towards large winter bioproduction induced by circulation changes appeared. The investigations performed represent the preliminary actions in the construction of an empirical ecological model of the NA which can be used in the sustainable economy of the region, as well as for validation of the numerical ecological model

  14. Seasonal changes in physiological responses and evaluation of "well-being" in the Venus clam Chamelea gallina from the Northern Adriatic Sea.

    PubMed

    Moschino, Vanessa; Marin, Maria Gabriella

    2006-12-01

    Chamelea gallina is an infaunal bivalve, widespread in sandy bottoms along Mediterranean coasts. It is an important economic resource for fisheries in the Adriatic, although in recent years over-fishing, and other concurrent factors, have dramatically decreased clam harvesting. In this context, it is of great interest to gain information on seasonal variations in the physiological performance of clams, for an overall evaluation of their well-being. In this study, laboratory experiments were performed to define allometric relationships and effects of temperature on clearance and respiration rates of C. gallina. The mean values of b coefficients were calculated and used to correlate physiological measurements to 'standard' body mass, when seasonally collected clams were analysed. The highest clearance rate (0.42 L h(-1)) was measured in clams collected in July 2000; the highest respiration rate (12.22 micromol O2 h(-1)) was observed in July 2001, leading to a negative scope for growth (-2.8 J h(-1)). The influence of environmental and endogenous factors, mostly reproduction, was discussed. Survival in air and condition indices, showing higher stress conditions in December 2000 and July 2001, were in good agreement with the other physiological measurements. The physiological responses examined in this study appear to be suitable for providing detailed indications on the well-being of C. gallina and may be useful for future studies aimed at eco-sustainable management of the resource. PMID:16959514

  15. Seasonal and spatial variations of 210Po and 210Pb activity concentrations in Mytilus galloprovincialis from Croatian coast of the Adriatic Sea.

    PubMed

    Rožmarić, Martina; Rogić, Matea; Benedik, Ljudmila; Štrok, Marko; Barišić, Delko

    2013-11-01

    Results of 2 years monitoring of (210)Po and (210)Pb activity concentrations in soft tissue of the species Mytilus galloprovincialis from Croatian part of the Adriatic coast are presented. The samples were collected at thirteen coastal stations (some of which are also a part of the Mediterranean Mussel Watch Project) in spring and autumn of 2010 and 2011. The collected mussels were ranging between 4 cm and 6 cm in shell length. After sample pre-treatment lead and polonium were radiochemically separated on Sr resin. (210)Po was determined by alpha-particle spectrometry and (210)Pb was determined, via (210)Bi, by a low-level gas proportional counter. The results of (210)Po activity concentrations were found to vary between (104±11) and (1421±81) Bq kg(-1) dry weight while (210)Pb activity concentrations were much lower and in range (8.2±5.3)-(94.1±29.8) Bq kg(-1) dry weight. Higher (210)Po and (210)Pb activity concentrations were determined in spring period. The inter-site differences seen in their activity concentrations can be due to natural background levels of sites. The (210)Po/(210)Pb activity concentration ratios in all cases exceeded unity for all mussel samples and ranged between 4.0 and 47.9. PMID:23932819

  16. Risk Assessment of Organochlorines in Mollusk from the Mediterranean and Red Sea Coasts of Egypt.

    PubMed

    El Nemr, Ahmed; El-Said, Ghada F; Khaled, Azza

    2016-04-01

    Organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) residues were studied in different mollusk species from the Egyptian Mediterranean and Red Sea coasts. The average levels of OCPs in mollusks comprised chlordanes, dieldrins, total endrin, endosulfan compounds, and methoxychlor (DECEM), dichlorodiphenyltrichloroethanes (DDTs), and, hexachlorocyclohexanes (HCHs). The averages of HCHs, DDTs, and polychlorinated biphenyls (PCBs) in mollusks from the Mediterranean Sea were 1.13±1.21, 1.30±1.27, and 1.40±0.93 ng/g, respectively; from the Red Sea, they were 0.62±0.90, 1.77±1.82, and 6.44±5.05 ng/g, respectively. The analysis of HCHs, DDTs, and PCBs in mollusks indicates a new usage of lindane, PCB congeners, and the input of technical HCH and aged DDT. The data showed that the Red Sea Coast was more affected by PCBs congeners than the Mediterranean Sea Coast, which may be attributed to the different activities along the two coastal areas. Mollusks in the Mediterranean Sea had higher dieldrins, total endrin, endosulfan compounds, and methoxychlor contents than those in the Red Sea. Interestingly, HCHs, DDTs, and PCBs levels were lower than those recommended for Swedish Food Regulation and U.S. Food and Drug Administration, which means that mollusks from these two coastal areas are safe as food. PMID:27131056

  17. Role of prokaryotic biomasses and activities in carbon and phosphorus cycles at a coastal, thermohaline front and in offshore waters (Gulf of Manfredonia, Southern Adriatic Sea).

    PubMed

    Monticelli, L S; Caruso, G; Decembrini, F; Caroppo, C; Fiesoletti, F

    2014-04-01

    The Western areas of the Adriatic Sea are subjected to inputs of inorganic nutrients and organic matter that can modify the trophic status of the waters and consequently, the microbiological processes involved in the carbon and phosphorus biogeochemical cycles, particularly in shallow coastal environments. To explore this topic, a survey was carried out during the spring of 2003 in a particular hydrodynamic area of the Gulf of Manfredonia, where the potential (P) and real (R) rates of four different microbial exoenzymatic activities (EEA) (α [αG] and ß glucosidases [ßG], leucine aminopeptidase [LAP], and alkaline phosphatase [AP]) as well as the P and R rates of prokaryotic heterotrophic production (PHP), AP as well as the P and R rates of PHP, primary production (PPnet), the prokaryotic and phototrophic stocks and basic hydrological parameters were examined. Three different water masses were found, with a thermohaline front (THF) being detected between the warmer and less saline coastal waters and colder and saltier offshore Adriatic waters. Under the general oligotrophic conditions of the entire Gulf, a decreasing gradient from the coastal toward the offshore areas was detected, with PHP, PPnet, stocks and EEA (αG, ßG, AP) being directly correlated with the temperature and inversely correlated with the salinity, whereas opposite relationships were observed for LAP activity. No enhancement of microbiological activities or stocks was observed at the THF. The use of P or R rates of microbiological activities, which decrease particularly for EEA, could result in discrepancies in interpreting the efficiency of several metabolic processes. PMID:24402364

  18. WMOP: The SOCIB Western Mediterranean Sea OPerational forecasting system

    NASA Astrophysics Data System (ADS)

    Renault, Lionel; Juza, Mélanie; Garau, Bartolomé; Sayol, Juan Manuel; Orfila, Alejandro; Tintoré, Joaquín

    2013-04-01

    Development of science based ocean-forecasting systems at global, regional, sub-regional and local scales is needed to increase our understanding of ocean processes and to support knowledge based management of the marine environment. In this context, WMOP (Western Mediterranean sea /Balearic OPerational system) is the forecasting subsystem component of SOCIB, the new Balearic Islands Coastal Observing and Forecasting System. The WMOP system is operational since the end of 2010. The ROMS model is forced every 3 hours with atmospheric forcing derived from AEMET/Hirlam and daily boundary conditions provided by MFS2 from MyOcean/MOON. Model domain is implemented over an area extending from Gibraltar strait to Corsica/Sardinia (from 6°W to 9°E and from 35°N to 44.5°N), including Balearic Sea and Gulf of Lion. The grid is 631 x 539 points with a resolution of ~1.5km, which allows good representation of mesoscale and submesoscale features (first baroclinic Rossby radius ~10-15 km) of key relevance in this region. The model has 30 sigma levels, and the vertical s coordinate is stretched for boundary layer resolution, also essential to capture extreme events water masses formation and dynamical effects. Bottom topography is derived from a 2' resolution database. Online validation procedures based on inter-comparison of model outputs against observing systems and reference models such as MFS and Mercator are used to assess at what level the numerical models are able to reproduce the features observed from in-situ systems and remote sensing. The intrinsic three-dimensional variability of the coastal ocean and open-ocean exchanges imply the need of muti-plaform observing systems covering a variety of scales. Fixed moorings provide a good temporal resolution but poor spatial coverage, while satellite products provide a good spatial coverage but just on the surface layer. Gliders can provide a reasonable spatial variability in both horizontal and vertical axes. Thus, inter

  19. Role of Marine Gateways in the Paleoceanography of the Miocene Mediterranean Sea; A Model Study

    NASA Astrophysics Data System (ADS)

    de la Vara, A.; Meijer, P. T.

    2015-12-01

    During the Miocene, due to the convergence of the African plate and the Eurasian plate, the Mediterranean region was subject to profound paleogeographic changes. The evolving coastline and bathymetry of the Mediterranean Sea and, in particular, the opening and closure of the marine connections between the Mediterranean and the outside oceans, triggered important changes in Mediterranean circulation and, indirectly, also affected the global-scale ocean circulation. Until about the Middle Miocene the proto-Mediterranean Sea was open to the Indo-Pacific Ocean through the so-called Indian Gateway. Although the exact age of closure of this gateway is still debated, it is accepted that it substantially affected the paleoceanography of the Mediterranean Sea. Later in time, during the Late Miocene, the Mediterranean was only connected to the Atlantic Ocean but by two marine corridors: the Betic and Rifian corridors. Closure of these narrow passages resulted in the Messinian Salinity Crisis, during which a sequence of evaporites was deposited throughout the Mediterranean basin. In this work we use a regional-scale ocean general circulation model (the Princeton Ocean Model) to gain insight into the role of the evolving gateways. The analysis focuses on large-scale (overturning) circulation, patterns of exchange in the gateways and properties of the Mediterranean water. By comparing our model results to geological data we are able to propose new scenarios or rule out previously proposed ones, and determine the conditions evidenced by the geological observations. More specifically we investigate two different topics: (i) the effects of shoaling and closure of the Indian Gateway and (ii) the functioning of the Late Miocene double gateway to the Atlantic.

  20. Elemental and biochemical composition of Nephrops norvegicus (Linnaeus 1758) larvae from the Mediterranean and Irish Seas

    NASA Astrophysics Data System (ADS)

    Rotllant, Guiomar; Anger, Klaus; Durfort, Mercè; Sardà, Francisco

    2004-10-01

    The Norway lobster, Nephrops norvegicus, is a commercially exploited decapod which is widely distributed throughout the north-eastern Atlantic and the Mediterranean Sea. Ovigerous females originating from the Mediterranean and the Irish Seas were held in the laboratory until larvae hatched. Biomass and biochemical composition, as well as digestive gland structure, were examined in newly hatched larvae from these two regions. In addition, previously published data from a North Sea population were included in our comparison. Elemental analyses showed that the absolute quantities of dry mass (DM), carbon (C), nitrogen (N) and hydrogen (H) (collectively referred to as CHN) per individual, and the C:N mass ratios, were significantly lower, while the relative CHN, protein and lipid values (in % of DM) were higher in samples from the Irish Sea compared to larvae originating from either the Mediterranean or the North Sea. As in CHN, the absolute level of protein per individual was higher in larvae from the Mediterranean, while no significant differences were observed in the individual lipid contents. Likewise, the digestive gland structure at hatching did not show any differences between study areas. Intraspecific variability in biomass and chemical composition of newly hatched larvae from different regions may be related to differential patterns of reproduction in regions with different climatic conditions. Lobster larvae hatch in the Mediterranean Sea predominantly in winter when both water temperature and planktonic food availability are at a minimum, while hatching in the Irish Sea occurs under more favourable conditions in spring. Hence, significantly higher wet mass, dry mass and protein values in Mediterranean larvae may represent adaptive traits allowing for early posthatching survival and development under food-limited conditions in an oligotrophic environment.

  1. Plankton in the open Mediterranean Sea: a review

    NASA Astrophysics Data System (ADS)

    Siokou-Frangou, I.; Christaki, U.; Mazzocchi, M. G.; Montresor, M.; Ribera D'Alcalá, M.; Vaqué, D.; Zingone, A.

    2010-05-01

    We present an overview of the plankton studies conducted during the last 25 years in the epipelagic offshore waters of the Mediterranean Sea. This quasi-enclosed sea is characterized by a rich and complex physical dynamics with distinctive traits, especially in regard to the thermohaline circulation. Recent investigations have basically confirmed the long-recognised oligotrophic nature of this sea, which increases along both the west-east and the north-south directions. Nutrient availability is low, especially for phosphorous (N:P up to 60), though this limitation may be buffered by inputs from highly populated coasts and from the atmosphere. Phytoplankton biomass, as chl a, generally displays low values (less than 0.2 μg chl a l-1) over large areas, with a modest late winter increase. A large bloom (up to 3 μg l-1) is observed throughout the late winter and spring exclusively in the NW area. Relatively high biomass values are recorded in fronts and cyclonic gyres. A deep chlorophyll maximum is a permanent feature for the whole basin, except during the late winter mixing. It is found at increasingly greater depths ranging from 30 m in the Alboran Sea to 120 m in the easternmost Levantine basin. Primary production reveals a west-east decreasing trend and ranges between 59 and 150 g C m-2 y-1 (in situ measurements). Overall, the basin is largely dominated by small autotrophs, microheterotrophs and egg-carrying copepod species. The microorganisms (phytoplankton, viruses, bacteria, flagellates and ciliates) and zooplankton components reveal a considerable diversity and variability over spatial and temporal scales, although the latter is poorly studied. Examples are the wide diversity of dinoflagellates and coccolithophores, the multifarious role of diatoms or picoeukaryotes, and the distinct seasonal or spatial patterns of the species-rich copepod genera or families which dominate the basin. Major dissimilarities between western and eastern basins have been

  2. Marine Caves of the Mediterranean Sea: A Sponge Biodiversity Reservoir within a Biodiversity Hotspot

    PubMed Central

    Gerovasileiou, Vasilis; Voultsiadou, Eleni

    2012-01-01

    Marine caves are widely acknowledged for their unique biodiversity and constitute a typical feature of the Mediterranean coastline. Herein an attempt was made to evaluate the ecological significance of this particular ecosystem in the Mediterranean Sea, which is considered a biodiversity hotspot. This was accomplished by using Porifera, which dominate the rocky sublittoral substrata, as a reference group in a meta-analytical approach, combining primary research data from the Aegean Sea (eastern Mediterranean) with data derived from the literature. In total 311 species from all poriferan classes were recorded, representing 45.7% of the Mediterranean Porifera. Demospongiae and Homoscleromorpha are highly represented in marine caves at the family (88%), generic (70%), and species level (47.5%), the latter being the most favored group along with Dictyoceratida and Lithistida. Several rare and cave-exclusive species were reported from only one or few caves, indicating the fragmentation and peculiarity of this unique ecosystem. Species richness and phylogenetic diversity varied among Mediterranean areas; the former was positively correlated with research effort, being higher in the northern Mediterranean, while the latter was generally higher in caves than in the overall sponge assemblages of each area. Resemblance analysis among areas revealed that cavernicolous sponge assemblages followed a pattern quite similar to that of the overall Mediterranean assemblages. The same pattern was exhibited by the zoogeographic affinities of cave sponges: species with Atlanto-Mediterranean distribution and Mediterranean endemics prevailed (more than 40% each), 70% of them having warm-water affinities, since most caves were studied in shallow waters. According to our findings, Mediterranean marine caves appear to be important sponge biodiversity reservoirs of high representativeness and great scientific interest, deserving further detailed study and protection. PMID:22808070

  3. The Po river water from the Alps to the Adriatic Sea (Italy): new insights from geochemical and isotopic (δ(18)O-δD) data.

    PubMed

    Marchina, Chiara; Bianchini, Gianluca; Natali, Claudio; Pennisi, Maddalena; Colombani, Nicolò; Tassinari, Renzo; Knoeller, Kay

    2015-04-01

    Although the Po river is the most important fluvial system of Northern Italy, the systematic geochemical and isotopic investigations of its water are rare and were never reported for the whole basin. The present contribution aims to fill this knowledge gap, reporting a comprehensive data set including oxygen and hydrogen stable isotopes as well as major and trace element concentration of dissolved species for 54 Po river water samples, mainly collected in different hydrological conditions (peak discharge in April, drought in August) at increasing distance from the source, i.e., from the upper part of the catchment to the terminal (deltaic) part of the river at the confluence with the Adriatic Sea. The isotopic compositions demonstrate that the predominant part of the runoff derives from the Alpine sector of the catchment through important tributaries such as the Dora Baltea, Ticino, Adda, and Tanaro rivers, whereas the contribution from the Apennines tributaries is less important. The geochemical and isotopic compositions show that the Po river water attains a homogeneous composition at ca. 100 km from the source. The average composition is characterized by δ(18)O -9.8‰, δD -66.2‰, total dissolved solid (TDS) 268 mg/L, and chloride 17 mg/L and by a general Ca-HCO3 hydrochemical facies, which is maintained for most of the river stream, only varying in the terminal part where the river is diverted in a complex deltaic system affected by more significant evaporation and mixing with saline water evidenced by higher TDS and chloride content (up to 8198 and 4197 mg/L, respectively). Geochemical and isotopic maps have been drawn to visualize spatial gradients, which reflect the evolution of the river water composition at progressive distance from the source; more detailed maps were focused on the deltaic part in order to visualize the processes occurring in the transitional zone toward the Adriatic Sea. The data also highlight anthropogenic contributions, mainly

  4. Environmental selection of protistan plankton communities in hypersaline anoxic deep-sea basins, Eastern Mediterranean Sea

    PubMed Central

    Filker, Sabine; Stock, Alexandra; Breiner, Hans-Werner; Edgcomb, Virginia; Orsi, William; Yakimov, Michail M; Stoeck, Thorsten

    2013-01-01

    High salt concentrations, absence of light, anoxia, and high hydrostatic pressure make deep hypersaline anoxic basins (DHABs) in the Eastern Mediterranean Sea one of the most polyextreme habitats on Earth. Taking advantage of the unique chemical characteristics of these basins, we tested the effect of environmental selection and geographic distance on the structure of protistan communities. Terminal restriction fragment length polymorphism (T-RFLP) analyses were performed on water samples from the brines and seawater/brine interfaces of five basins: Discovery, Urania, Thetis, Tyro, and Medee. Using statistical analyses, we calculated the partitioning of diversity among the ten individual terminal restriction fragment (T-RF) profiles, based on peak abundance and peak incidence. While a significant distance effect on spatial protistan patterns was not detected, hydrochemical gradients emerged as strong dispersal barriers that likely lead to environmental selection in the DHAB protistan plankton communities. We identified sodium, magnesium, sulfate, and oxygen playing in concerto as dominant environmental drivers for the structuring of protistan plankton communities in the Eastern Mediterranean DHABs. PMID:23239531

  5. Environmental selection of protistan plankton communities in hypersaline anoxic deep-sea basins, Eastern Mediterranean Sea.

    PubMed

    Filker, Sabine; Stock, Alexandra; Breiner, Hans-Werner; Edgcomb, Virginia; Orsi, William; Yakimov, Michail M; Stoeck, Thorsten

    2013-02-01

    High salt concentrations, absence of light, anoxia, and high hydrostatic pressure make deep hypersaline anoxic basins (DHABs) in the Eastern Mediterranean Sea one of the most polyextreme habitats on Earth. Taking advantage of the unique chemical characteristics of these basins, we tested the effect of environmental selection and geographic distance on the structure of protistan communities. Terminal restriction fragment length polymorphism (T-RFLP) analyses were performed on water samples from the brines and seawater/brine interfaces of five basins: Discovery, Urania, Thetis, Tyro, and Medee. Using statistical analyses, we calculated the partitioning of diversity among the ten individual terminal restriction fragment (T-RF) profiles, based on peak abundance and peak incidence. While a significant distance effect on spatial protistan patterns was not detected, hydrochemical gradients emerged as strong dispersal barriers that likely lead to environmental selection in the DHAB protistan plankton communities. We identified sodium, magnesium, sulfate, and oxygen playing in concerto as dominant environmental drivers for the structuring of protistan plankton communities in the Eastern Mediterranean DHABs. PMID:23239531

  6. SWASV speciation of Cd, Pb and Cu for the determination of seawater contamination in the area of the Nicole shipwreck (Ancona coast, Central Adriatic Sea).

    PubMed

    Annibaldi, Anna; Illuminati, Silvia; Truzzi, Cristina; Scarponi, Giuseppe

    2011-12-01

    The study reports for the first time on the heavy metal contamination of the waters surrounding a shipwreck lying on the sea floor. Square wave anodic stripping voltammetry has been used for a survey of the total and dissolved Cd, Pb and Cu contents of the seawater at the site of the sinking of the Nicole M/V (Coastal Adriatic Sea, Italy). Results show that the hulk has a considerable impact as regards all three metals in the bottom water, especially for the particulate fraction concentrations, which increased by factors of ≈ 9 (Cd), ≈ 3 (Pb) and ≈ 5 (Cu). The contaminated plume extended downstream for about 2 miles. Much lower contamination was observed for dissolved bottom concentrations; nevertheless Pb (0.56 ± 0.03 nmol/L) is higher than the Italian legal limits established for 2015 and Cd (0.23 ± 0.03 nmol/L) is very close the limit of Cd will be exceeded if the hulk is not removed. PMID:21982428

  7. Grandidierella bonnieroides Stephensen, 1948 (Amphipoda, Aoridae)-first record of an established population in the Mediterranean Sea.

    PubMed

    Brutto, Sabrina Lo; Iaciofano, Davide; Lubinevsky, Hadas; Galil, Bella S

    2016-01-01

    The first record in the Mediterranean Sea of the invasive aorid amphipod crustacean Grandidierella bonnieroides is presented. A widespread circumtropical species, recorded off the Saudi coast of the Arabian Gulf, the Red Sea and the Suez Canal, it may have been introduced into the Mediterranean through the Suez Canal. This tube-builder species of soft bottoms recently established a population in the polluted Haifa Bay, Israel. Further, this is the first Mediterranean record of the genus. PMID:27394471

  8. Seasonal bathymetric migrations of deep-sea fishes and decapod crustaceans in the NW Mediterranean Sea

    NASA Astrophysics Data System (ADS)

    Aguzzi, J.; Company, J. B.; Bahamon, N.; Flexas, M. M.; Tecchio, S.; Fernandez-Arcaya, U.; García, J. A.; Mechó, A.; Koenig, S.; Canals, M.

    2013-11-01

    Seasonal variations in the photophase length seem to drive migrations of marine animals, a phenomenon still largely unknown in deep-sea fishes and decapod crustaceans. Here, we report depth-oriented migrations of species living in the continental slope of the NW Mediterranean after repeated trawl sampling between 900 and 1500 m depths in four seasons. To understand the variations in the catchability of animals as a function of water depth, we analysed the relationship between population depth shifts and environmental factors by performing a multiparametric habitat monitoring at sea surface (PAR), in the water column (temperature and salinity), and on the seabed (organic matter flux and total mass flux). Significant connections are studied by NMDS and GAM analyses. Bathymetric changes in most targeted species are identified from winter, when distribution was the deepest, to spring and summer, and finally autumn, when the shallowest distribution was observed prior to a sudden bathymetric retreat. The analysis of size-class frequency distributions (Kolmogorov-Smirnov test) discards an effect of the juvenile recruitment on these bathymetric changes. Which environmental factor imparts seasonality to these depth-oriented migrations has not yet been clarified. A strong connection is found with water temperature and salinity, associated to flow of the Levantine Intermediate Water (LIW) and the Western Mediterranean Deep Water (WMDW). The studied depth range was affected by seasonal fluctuations of both water masses and the interphase amongst them. LIW showed a stronger seasonal pattern, getting warmer, saltier in autumn and fresher in winter. The migration of most species towards shallower depths in spring, summer and autumn, and the sudden migration to deeper grounds in winter could therefore be related to changes in LIW temperature and salinity.

  9. Mediterranean Sea response to climate change in an ensemble of twenty first century scenarios

    NASA Astrophysics Data System (ADS)

    Adloff, Fanny; Somot, Samuel; Sevault, Florence; Jordà, Gabriel; Aznar, Roland; Déqué, Michel; Herrmann, Marine; Marcos, Marta; Dubois, Clotilde; Padorno, Elena; Alvarez-Fanjul, Enrique; Gomis, Damià

    2015-11-01

    The Mediterranean climate is expected to become warmer and drier during the twenty-first century. Mediterranean Sea response to climate change could be modulated by the choice of the socio-economic scenario as well as the choice of the boundary conditions mainly the Atlantic hydrography, the river runoff and the atmospheric fluxes. To assess and quantify the sensitivity of the Mediterranean Sea to the twenty-first century climate change, a set of numerical experiments was carried out with the regional ocean model NEMOMED8 set up for the Mediterranean Sea. The model is forced by air-sea fluxes derived from the regional climate model ARPEGE-Climate at a 50-km horizontal resolution. Historical simulations representing the climate of the period 1961-2000 were run to obtain a reference state. From this baseline, various sensitivity experiments were performed for the period 2001-2099, following different socio-economic scenarios based on the Special Report on Emissions Scenarios. For the A2 scenario, the main three boundary forcings (river runoff, near-Atlantic water hydrography and air-sea fluxes) were changed one by one to better identify the role of each forcing in the way the ocean responds to climate change. In two additional simulations (A1B, B1), the scenario is changed, allowing to quantify the socio-economic uncertainty. Our 6-member scenario simulations display a warming and saltening of the Mediterranean. For the 2070-2099 period compared to 1961-1990, the sea surface temperature anomalies range from +1.73 to +2.97 °C and the SSS anomalies spread from +0.48 to +0.89. In most of the cases, we found that the future Mediterranean thermohaline circulation (MTHC) tends to reach a situation similar to the eastern Mediterranean Transient. However, this response is varying depending on the chosen boundary conditions and socio-economic scenarios. Our numerical experiments suggest that the choice of the near-Atlantic surface water evolution, which is very uncertain in

  10. MedArgo: a drifting profiler program in the Mediterranean Sea

    NASA Astrophysics Data System (ADS)

    Poulain, P.-M.; Barbanti, R.; Font, J.; Cruzado, A.; Millot, C.; Gertman, I.; Griffa, A.; Molcard, A.; Rupolo, V.; Le Bras, S.; Petit de La Villeon, L.

    2007-08-01

    In the framework of the EU-funded MFSTEP project, autonomous drifting profilers were deployed throughout the Mediterranean Sea to collect temperature and salinity profile data and to measure subsurface currents. The realization of this profiler program in the Mediterranean, referred to as MedArgo, is described and assessed using data collected between June 2004 and December 2006 (including more than 2000 profiles). Recommendations are provided for the permanent future implementation of MedArgo in support of operational oceanography in the Mediterranean Sea. More than twenty drifting profilers were deployed from research vessels and ships-of-opportunity in most areas of the Mediterranean. They were all programmed to execute 5-day cycles with a drift at a parking depth of 350 m and CTD profiles from either 700 or 2000 m up to the surface. They stayed at the sea surface for about 6 h to be localised by, and transmit the data to, the Argos satellite system. The temperature and salinity data obtained with pumped Sea-Bird CTD instruments were processed and made available to the scientific community and to operational users in near-real time using standard Argo protocols, and were assimilated into Mediterranean numerical forecasting models. In general, the cycling and sampling characteristics chosen for the MedArgo profilers were found to be adequate for the Mediterranean. However, it is strongly advised to use GPS and global cellular phone telemetry or the future Argos bi-directional satellite system in order to avoid data compression and losses, for the continuation of the Mediterranean drifting profiler program.

  11. New developments in spatial interpolation methods of Sea-Level Anomalies in the Mediterranean Sea

    NASA Astrophysics Data System (ADS)

    Troupin, Charles; Barth, Alexander; Beckers, Jean-Marie; Pascual, Ananda

    2014-05-01

    The gridding of along-track Sea-Level Anomalies (SLA) measured by a constellation of satellites has numerous applications in oceanography, such as model validation, data assimilation or eddy tracking. Optimal Interpolation (OI) is often the preferred method for this task, as it leads to the lowest expected error and provides an error field associated to the analysed field. However, the numerical cost of the method may limit its utilization in situations where the number of data points is significant. Furthermore, the separation of non-adjacent regions with OI requires adaptation of the code, leading to a further increase of the numerical cost. To solve these issues, the Data-Interpolating Variational Analysis (DIVA), a technique designed to produce gridded from sparse in situ measurements, is applied on SLA data in the Mediterranean Sea. DIVA and OI have been shown to be equivalent (provided some assumptions on the covariances are made). The main difference lies in the covariance function, which is not explicitly formulated in DIVA. The particular spatial and temporal distributions of measurements required adaptation in the Software tool (data format, parameter determinations, ...). These adaptation are presented in the poster. The daily analysed and error fields obtained with this technique are compared with available products such as the gridded field from the Archiving, Validation and Interpretation of Satellite Oceanographic data (AVISO) data server. The comparison reveals an overall good agreement between the products. The time evolution of the mean error field evidences the need of a large number of simultaneous altimetry satellites: in period during which 4 satellites are available, the mean error is on the order of 17.5%, while when only 2 satellites are available, the error exceeds 25%. Finally, we propose the use sea currents to improve the results of the interpolation, especially in the coastal area. These currents can be constructed from the bathymetry

  12. The Influence of Allochthonous Leaf Detritus on the Occurrence of Crustacean Detritivores in the Soft-bottom Macrobenthos of the Po River Delta Area (northwestern Adriatic Sea)

    NASA Astrophysics Data System (ADS)

    Mancinelli, G.; Rossi, L.

    2002-05-01

    Core samples were examined quarterly at two coastal sites (S1 and S2) and at an offshore station (S3) located in the Po River delta area (northwestern Adriatic Sea). Analyses focused on (i) occurrence of coarse detritus of allochthonous origin in the sedimentary matrix and (ii) the relative influence of macrodetritus enrichment and other environmental factors on the vagile macrofauna. Plant debris occurred in site S1 sediments only in summer and autumn; in contrast, fragments of the phanerogams Cymodocea nodosa and Zostera spp. were found in site S2 sediment throughout the sampling period. Sediments from the offshore site S3 were characterized by negligible plant material, even though in summer and autumn samples debris of continental origin was observed. Even though leaf detritus occurrence at site S2 was ∼5-fold higher compared to the other coastal site S1, it did not influence the total organic matter and its distribution among grain-size classes. Conversely, the specific organic content of dimensional fractions provided an effective assessment of detritus enrichment processes occurring at the two coastal sites. A group of brackish-originated crustaceans (i.e. the amphipods Gammarus insensibilis and G. aequicauda and the isopod Idotea baltica) was the main determinant of among-site multivariate differences in the vagile macrofauna; depositivorous ophiuroids accounted for the residual differences observed during the study period. The analysis of taxa abundance and individual body size indicated that in both site S1 and S3 macrodetritus advection to the benthic system corresponded with passive dispersal of brackish crustaceans, that provided a negligible contribution to the macrobenthic production. In contrast, in site S2 allochthonous inputs from marginal environments could have represented the key factor for the persistence of an authochthonous population of Gammarus insensibilis. The amphipod provided a considerable (19·4%) contribution to the total

  13. Initiation of a severe thunderstorm over the Mediterranean Sea

    NASA Astrophysics Data System (ADS)

    Cohuet, J. B.; Romero, R.; Homar, V.; Ducrocq, V.; Ramis, C.

    2011-06-01

    The Mediterranean basin is regularly affected by severe weather associated with deep convection. Although convective systems are usually linked to coastal orography, some severe thunderstorms develop and mature over the sea. A recent example is the severe thunderstorm that affected the island of Mallorca in the afternoon of 4 October 2007. The storm formed early in the morning offshore of Murcia, and steadily became organized into a squall line. Arriving in Palma city, this squall line produced severe gusts, heavy rain and several tornadoes. The initiation and evolution of convection in these kinds of maritime events depend on both synoptic and mesoscale features. Representing such interactions is a challenge for numerical weather prediction. The aim of this study is to determine the prominent factors involved in the initiation and evolution of the damaging squall line, by means of high resolution numerical experiments. We also focus on squall line mesovortices to explain the potential for tornado development and the role of Mallorcan orography on their evolution. Simulations performed with the mesoscale model Méso-NH allowed relevant mechanisms for initiation and development of the strong squall line to be identified. The squall line initiates in an area with conditional instability, characterized by a cut-off and a southerly jet aloft and by moist, warm air at low-levels along a front. In addition, the area of low-level convergence offshore of Murcia, associated with the front and enhanced by a low downstream of the Atlas range, was shown to be crucial during the early stage of the convective system. The dry layer in the mid-troposphere and the strong sheared environment provide elements for understanding the development of such a damaging squall line. Moreover, a very high resolution experiment (600 m mesh) gave a very realistic representation of the squall line, including mesovortices ahead of the gust front, which confirmed the potential of this strong

  14. Global warming and mass mortalities of benthic invertebrates in the Mediterranean Sea.

    PubMed

    Rivetti, Irene; Fraschetti, Simonetta; Lionello, Piero; Zambianchi, Enrico; Boero, Ferdinando

    2014-01-01

    Satellite data show a steady increase, in the last decades, of the surface temperature (upper few millimetres of the water surface) of the Mediterranean Sea. Reports of mass mortalities of benthic marine invertebrates increased in the same period. Some local studies interpreted the two phenomena in a cause-effect fashion. However, a basin-wide picture of temperature changes combined with a systematic assessment on invertebrate mass mortalities was still lacking. Both the thermal structure of the water column in the Mediterranean Sea over the period 1945-2011 and all documented invertebrate mass mortality events in the basin are analysed to ascertain if: 1- documented mass mortalities occurred under conditions of positive temperature trends at basin scale, and 2- atypical thermal conditions were registered at the smaller spatial and temporal scale of mass mortality events. The thermal structure of the shallow water column over the last 67 years was reconstructed using data from three public sources: MEDAR-MEDATLAS, World Ocean Database, MFS-VOS programme. A review of the mass mortality events of benthic invertebrates at Mediterranean scale was also carried out. The analysis of in situ temperature profiles shows that the Mediterranean Sea changed in a non-homogeneous fashion. The frequency of mass mortalities is increasing. The areas subjected to these events correspond to positive thermal anomalies. Statistically significant temperature trends in the upper layers of the Mediterranean Sea show an increase of up to 0.07°C/yr for a large fraction of the basin. Mass mortalities are consistent with both the temperature increase at basin scale and the thermal changes at local scale, up to 5.2°C. Our research supports the existence of a causal link between positive thermal anomalies and observed invertebrate mass mortalities in the Mediterranean Sea, invoking focused mitigation initiatives in sensitive areas. PMID:25535973

  15. Foraminiferal Range Expansions: The Mediterranean Sea as a natural laboratory for climate induced invasions

    NASA Astrophysics Data System (ADS)

    Hortense Mouanga, Gloria; Langer, Martin R.

    2015-04-01

    Climate change and biological invasions are key processes that modify biodiversity. One of the most severely affected areas of global change is the Mediterranean Sea, where global warming and the opening of the Suez Canal triggered a mass invasion of tropical Red Sea taxa into Mediterranean territories. Climate models prognosticate that the Mediterranean Sea will be one of the most affected ocean regions and may thus serve as a natural laboratory of future global changes. Among the key taxa that are rapidly expanding their latitudinal range in the Mediterranean Sea are symbiont-bearing foraminifera of the genus Amphistegina. Their range expansion strongly correlates with rising sea surface temperatures and mirrors processes of global change. Amphisteginid foraminifera are among the most prolific foraminiferal species and contribute significantly to shallow-water carbonate sediments. Given their prominent environmental role, rapid biogeographic range expansion, and impact on native ecosystems, amphisteginid range expansion and invasion into new territory are likely to trigger changes in ecosystem functioning. Among the uncertainties, it is not known whether all parts of the Mediterranean will be affected equally and to what extent amphisteginid invasions will impact native biotas. We have initiated a new baseline study to explore the effects of invasive amphisteginids on native foraminiferal biotas and to monitor expansion rates and effects on ecosystem functioning along the current range expansion front. We will present new data on recent shift along the range expansion front and discuss cascading effects on community structures and species richness of native foraminiferal biotas. The magnitude and effects that climate change will have on the Mediterranean foraminiferal faunas may ultimately serve as an example of what would happen along expansion fronts in global oceans.

  16. Global Warming and Mass Mortalities of Benthic Invertebrates in the Mediterranean Sea

    PubMed Central

    Rivetti, Irene; Fraschetti, Simonetta; Lionello, Piero; Zambianchi, Enrico; Boero, Ferdinando

    2014-01-01

    Satellite data show a steady increase, in the last decades, of the surface temperature (upper few millimetres of the water surface) of the Mediterranean Sea. Reports of mass mortalities of benthic marine invertebrates increased in the same period. Some local studies interpreted the two phenomena in a cause-effect fashion. However, a basin-wide picture of temperature changes combined with a systematic assessment on invertebrate mass mortalities was still lacking. Both the thermal structure of the water column in the Mediterranean Sea over the period 1945–2011 and all documented invertebrate mass mortality events in the basin are analysed to ascertain if: 1- documented mass mortalities occurred under conditions of positive temperature trends at basin scale, and 2- atypical thermal conditions were registered at the smaller spatial and temporal scale of mass mortality events. The thermal structure of the shallow water column over the last 67 years was reconstructed using data from three public sources: MEDAR-MEDATLAS, World Ocean Database, MFS-VOS programme. A review of the mass mortality events of benthic invertebrates at Mediterranean scale was also carried out. The analysis of in situ temperature profiles shows that the Mediterranean Sea changed in a non-homogeneous fashion. The frequency of mass mortalities is increasing. The areas subjected to these events correspond to positive thermal anomalies. Statistically significant temperature trends in the upper layers of the Mediterranean Sea show an increase of up to 0.07°C/yr for a large fraction of the basin. Mass mortalities are consistent with both the temperature increase at basin scale and the thermal changes at local scale, up to 5.2°C. Our research supports the existence of a causal link between positive thermal anomalies and observed invertebrate mass mortalities in the Mediterranean Sea, invoking focused mitigation initiatives in sensitive areas. PMID:25535973

  17. Steric and Mass-Induced Sea Level Variations in the Mediterranean Sea, Revisited

    NASA Astrophysics Data System (ADS)

    Garcia-Garcia, D.; Chao, B. F.; Boy, J.-P.

    2009-04-01

    Observed by radar altimetry satellites such as TOPEX/Poseidon (T/P) and Jason-1/2, the total Sea Level Variations (SLV) are produced by a combination of the steric and mass-induced components. The steric SLV can be computed from in situ measurements of temperature and salinity profiles, or from Ocean General Circulation Models (OGCM) that can assimilate those measurements. Mass-induced SLV can be estimated, since 2002, from Time-Variable Gravity (TVG) measurements by the GRACE satellite mission. This methodology has been successfully applied in estimation of the global ocean mass-induced SLV. However, some difficulties arise when studying semi-enclosed basins due to land aliasing of the GRACE TVG signal. The problem is specially complicated in the Mediterranean Sea as reported in previous studies. We revisit this problem analyzing release 4 of the GRACE data set, which represents a time series 3 times longer than in previous studies, by means of new and more efficient filters to reduce the noise in the high degree and order spherical harmonics coefficients. The seasonal and non-seasonal signals are analyzed. From the comparison of GRACE with altimetry data a general underestimation of the steric term is observed in the OGCMs used.

  18. Steric and mass-induced sea level variations in the Mediterranean Sea revisited

    NASA Astrophysics Data System (ADS)

    GarcíA-GarcíA, D.; Chao, B. F.; Boy, J.-P.

    2010-12-01

    The total sea level variation (SLV) is the combination of steric and mass-induced SLV, whose exact shares are key to understanding the oceanic response to climate system changes. Total SLV can be observed by radar altimetry satellites such as TOPEX/POSEIDON and Jason 1/2. The steric SLV can be computed through temperature and salinity profiles from in situ measurements or from ocean general circulation models (OGCM), which can assimilate the said observations. The mass-induced SLV can be estimated from its time-variable gravity (TVG) signals. We revisit this problem in the Mediterranean Sea estimating the observed, steric, and mass-induced SLV, for the latter we analyze the latest TVG data set from the GRACE (Gravity Recovery and Climate Experiment) satellite mission launched in 2002, which is 3.5 times longer than in previous studies, with the application of a two-stage anisotropic filter to reduce the noise in high-degree and -order spherical harmonic coefficients. We confirm that the intra-annual total SLV are only produced by water mass changes, a fact explained in the literature as a result of the wind field around the Gibraltar Strait. The steric SLV estimated from the residual of "altimetry minus GRACE" agrees in phase with that estimated from OGCMs and in situ measurements, although showing a higher amplitude. The net water fluxes through both the straits of Gibraltar and Sicily have also been estimated accordingly.

  19. Investigating the impact of surface wave breaking on modeling the trajectories of drifters in the northern Adriatic Sea during a wind-storm event

    USGS Publications Warehouse

    Carniel, S.; Warner, J.C.; Chiggiato, J.; Sclavo, M.

    2009-01-01

    An accurate numerical prediction of the oceanic upper layer velocity is a demanding requirement for many applications at sea and is a function of several near-surface processes that need to be incorporated in a numerical model. Among them, we assess the effects of vertical resolution, different vertical mixing parameterization (the so-called Generic Length Scale -GLS- set of k-??, k-??, gen, and the Mellor-Yamada), and surface roughness values on turbulent kinetic energy (k) injection from breaking waves. First, we modified the GLS turbulence closure formulation in the Regional Ocean Modeling System (ROMS) to incorporate the surface flux of turbulent kinetic energy due to wave breaking. Then, we applied the model to idealized test cases, exploring the sensitivity to the above mentioned factors. Last, the model was applied to a realistic situation in the Adriatic Sea driven by numerical meteorological forcings and river discharges. In this case, numerical drifters were released during an intense episode of Bora winds that occurred in mid-February 2003, and their trajectories compared to the displacement of satellite-tracked drifters deployed during the ADRIA02-03 sea-truth campaign. Results indicted that the inclusion of the wave breaking process helps improve the accuracy of the numerical simulations, subject to an increase in the typical value of the surface roughness z0. Specifically, the best performance was obtained using ??CH = 56,000 in the Charnok formula, the wave breaking parameterization activated, k-?? as the turbulence closure model. With these options, the relative error with respect to the average distance of the drifter was about 25% (5.5 km/day). The most sensitive factors in the model were found to be the value of ??CH enhanced with respect to a standard value, followed by the adoption of wave breaking parameterization and the particular turbulence closure model selected. ?? 2009 Elsevier Ltd.

  20. Saharan dust deposition may affect phytoplankton growth in the Mediterranean sea at ecological time scales.

    PubMed

    Gallisai, Rachele; Peters, Francesc; Volpe, Gianluca; Basart, Sara; Baldasano, José Maria

    2014-01-01

    The surface waters of the Mediterranean Sea are extremely poor in the nutrients necessary for plankton growth. At the same time, the Mediterranean Sea borders with the largest and most active desert areas in the world and the atmosphere over the basin is subject to frequent injections of mineral dust particles. We describe statistical correlations between dust deposition over the Mediterranean Sea and surface chlorophyll concentrations at ecological time scales. Aerosol deposition of Saharan origin may explain 1 to 10% (average 5%) of seasonally detrended chlorophyll variability in the low nutrient-low chlorophyll Mediterranean. Most of the statistically significant correlations are positive with main effects in spring over the Eastern and Central Mediterranean, conforming to a view of dust events fueling needed nutrients to the planktonic community. Some areas show negative effects of dust deposition on chlorophyll, coinciding with regions under a large influence of aerosols from European origin. The influence of dust deposition on chlorophyll dynamics may become larger in future scenarios of increased aridity and shallowing of the mixed layer. PMID:25333783

  1. Saharan Dust Deposition May Affect Phytoplankton Growth in the Mediterranean Sea at Ecological Time Scales

    PubMed Central

    Gallisai, Rachele; Peters, Francesc; Volpe, Gianluca; Basart, Sara; Baldasano, José Maria

    2014-01-01

    The surface waters of the Mediterranean Sea are extremely poor in the nutrients necessary for plankton growth. At the same time, the Mediterranean Sea borders with the largest and most active desert areas in the world and the atmosphere over the basin is subject to frequent injections of mineral dust particles. We describe statistical correlations between dust deposition over the Mediterranean Sea and surface chlorophyll concentrations at ecological time scales. Aerosol deposition of Saharan origin may explain 1 to 10% (average 5%) of seasonally detrended chlorophyll variability in the low nutrient-low chlorophyll Mediterranean. Most of the statistically significant correlations are positive with main effects in spring over the Eastern and Central Mediterranean, conforming to a view of dust events fueling needed nutrients to the planktonic community. Some areas show negative effects of dust deposition on chlorophyll, coinciding with regions under a large influence of aerosols from European origin. The influence of dust deposition on chlorophyll dynamics may become larger in future scenarios of increased aridity and shallowing of the mixed layer. PMID:25333783

  2. The tropical caprellid amphipod Paracaprella pusilla: a new alien crustacean in the Mediterranean Sea

    NASA Astrophysics Data System (ADS)

    Ros, Macarena; Vázquez-Luis, Maite; Guerra-García, José Manuel

    2013-12-01

    Paracaprella pusilla Mayer (Fauna und Flora des Golfes von Neapel 17:1-55, 1890), originally described from Brazil, is one of the most abundant caprellid amphipod species in tropical and subtropical seas around the world. During a survey of caprellid amphipods from marinas along the Balearic Island (Western Mediterranean Sea) carried out between November 2011 and August 2012, we found two established populations of P. pusilla in Mallorca and Ibiza, respectively. So far, its occurrence in European waters was reported only from southwestern Spain in 2010. This record represents a northward range expansion of the species' distribution, which is found for the first time in the Mediterranean. This is also the first record of the genus Paracaprella in the Mediterranean Sea. The most probable introduction vector was ship fouling. We also found the invasive caprellid Caprella scaura Templeton (Trans Entomol Soc Lond 1:185-198, 1836) in Mallorca and Menorca, which is recorded for the first time in the Balearic Islands, confirming its rapid expansion along the Mediterranean. When comparing reproductive traits between both alien species, we found that P. pusilla has a higher fecundity than C. scaura for the same female size. Taking into account this evidence, the species may be expected to appear in other Mediterranean and adjacent areas.

  3. Gyrodactylus orecchiae sp. n. (Monogenea: Gyrodactylidae) from farmed populations of gilthead seabream (Sparus aurata) in the Adriatic Sea.

    PubMed

    Paladini, Giuseppe; Cable, Joanne; Fioravanti, Maria L; Faria, Patricia J; Di Cave, David; Shinn, Andrew P

    2009-03-01

    Gyrodactylus orecchiae sp. n. (Monogenea, Gyrodactylidae) is described from the skin, fins, eyes and gills of juvenile Sparus aurata L. (gilthead seabream) following two outbreaks of gyrodactylosis amongst stocks held in inshore floating cages on the Adriatic coast of Albania and Croatia. Fish were heavily infected (1000+ gyrodactylids/fish) with G. orecchiae which reportedly resulted in approximately 2-10% mortality amongst the infected stock. Morphologically, the haptoral hooks of G. orecchiae most closely resemble those of Gyrodactylus arcuatus Bychowsky, 1933 in the approximate shape of the ventral bar with its pronounced ventral bar processes and marginal hook sickles which possess a square line to the inner edge of the sickle blade and large rounded heels. The marginal hooks are also morphologically similar to those of Gyrodactylus quadratidigitus Longshaw, Pursglove et Shinn, 2003 and Gyrodactylus colemanensis Mizelle et Kritsky, 1967, but G. orecchiae can be readily discriminated from all three species by the characteristic infolding of the hamuli roots and the shape of the marginal hook sickle. Molecular sequencing of the ITS1, 5.8S, ITS2 regions (513+157+404 bp, respectively) of G. orecchiae and alignment with other gyrodactylids for which these same genomic regions have been determined, suggests that this is a new species. No similarities were found when the ITS1 region of G. orecchiae was compared with 84 species of Gyrodactylus available on GenBank. PMID:19391328

  4. Distribution of persistent organic pollutants (POPs) in cultured mussels from the Croatian coast of the Adriatic Sea.

    PubMed

    Herceg-Romanić, Snježana; Kljaković-Gašpić, Zorana; Klinčić, Darija; Ujević, Ivana

    2014-11-01

    In this study we investigated the distribution of 7 organochlorine pesticides (OCPs) and 17 polychlorinated biphenyl (PCBs) congeners in the edible tissue of the blue mussels (Mytilusgalloprovincialis) collected at 15 shellfish breeding farms and 1 harvesting area along the Croatian Adriatic coast. All analyzed OCPs were found in all samples (0.011-1.47 ng g(-)(1) w.wt.). Concentrations of PCB congeners in positive samples ranged between 0.007 and 7.66 ng g(-)(1) w.wt. The most abundant compounds were γ-HCH, PCB-138 and PCB-153. Overall levels of PCBs and OCPs were in the lower end of the concentration ranges reported in literature. Significant differences of all contaminants were recorded between seasons, with higher values in the warmer part of the year. Results of the evaluation of the risks to human health associated with consumption of the mussels containing organic contaminants suggest that the levels of these compounds in mussels do not pose any threat for consumers of cultivated mussels. PMID:25113185

  5. Holocene sea level changes at the coast of dor, southeast mediterranean.

    PubMed

    Sneh, Y; Klein, M

    1984-11-16

    Geological, geomorphological, and archeological data of changes in sea level during the Holocene at the Mediterranean coast of Dor provide a eustatic curve of the region. This curve shows that sea level was approximately 2 meters below the present level 4000 years ago, rose to 1 meter below the present level 3000 years ago, and was 1 meter higher than the present level 1500 years ago. It then dropped to 1 meter below the present level about 800 years ago. PMID:17759891

  6. Population Genetic History of Aristeus antennatus (Crustacea: Decapoda) in the Western and Central Mediterranean Sea

    PubMed Central

    Marra, Annamaria; Mona, Stefano; Sà, Rui M.; D’Onghia, Gianfranco; Maiorano, Porzia

    2015-01-01

    Aristeus antennatus is an ecologically and economically important deep-water species in the Mediterranean Sea. In this study we investigated the genetic variability of A. antennatus sampled from 10 sampling stations in the Western and Central Mediterranean. By comparing our new samples with available data from the Western area, we aim to identify potential genetic stocks of A. antennatus and to reconstruct its historical demography in the Mediterranean. We analyzed two regions of mitochondrial DNA in 319 individuals, namely COI and 16S. We found two main results: i) the genetic diversity values consistent with previous data within the Mediterranean and the absence of barriers to gene flow within the Mediterranean Sea; ii) a constant long-term effective population size in almost all demes but a strong signature of population expansion in the pooled sample about 50,000 years B.P./ago. We propose two explanation for our results. The first is based on the ecology of A. antennatus. We suggest the existence of a complex meta-population structured into two layers: a deeper-dwelling stock, not affected by fishing, which preserves the pattern of historical demography; and genetically homogeneous demes inhabiting the fishing grounds. The larval dispersal, adult migration and continuous movements of individuals from “virgin” deeper grounds not affected by fishing to upper fishing areas support an effective ‘rescue effect’ contributing to the recovery of the exploited stocks and explain their genetic homogeneity throughout the Mediterranean Sea. The second is based on the reproduction model of this shrimp: the high variance in offspring production calls for a careful interpretation of the data observed under classical population genetics and Kingman’s coalescent. In both cases, management policies for A. antennatus will therefore require careful evaluation of the meta-population dynamics of all stocks in the Mediterranean. In the future, it will be particularly

  7. Understanding dynamic of biogeochemical properties in the northern Adriatic Sea by using self-organizing maps and k-means clustering

    NASA Astrophysics Data System (ADS)

    Solidoro, Cosimo; Bandelj, Vinko; Barbieri, Pierluigi; Cossarini, Gianpiero; Fonda Umani, Serena

    2007-07-01

    The dynamic of biogeochemical properties in a coastal area of the northern Adriatic Sea (Gulf of Trieste) is analyzed through (1) identification of a small number of water typology classes and classification of samples, obtained by means of a novel multivariate classification procedure based on a combination of Artificial Neural Networks (ANN) and "traditional" clusterization algorithms, (2) interpretation of each class based on biogeochemical properties and ecological phenomena likely to occur in the water body, and (3) discussion of time evolution and spatial distribution of water classes which summarized and provided indications on the system's space and time evolution. Basing itself on a multivariate comparison, the Self-Organizing Map (SOM) grouped 1292 samples collected in a 3-year-long monitoring program in 187 sets and identified a representative synthetic sample for each group. These groups were further classified in seven clusters, which identified the water typology. The complexity of the space and time coevolution of 12 variables was so reduced to variation of one categorical variable. Results included an objectively derived typology of water masses and their typical temporal succession, a spatial dividing based on biogeochemical processes, a conceptual scheme of biogeochemistry in the Gulf. Results clearly indicated the importance of river input in triggering plankton blooms and pointed out that trophodynamics followed current paradigms of marine ecosystem functioning, with shifts from conditions dominated by classical food chain to situations in which most of the energy flowed through the autotrophic and heterotrophic parts of the microbial food web.

  8. Petroleum systems of the Po Basin Province of northern Italy and the northern Adriatic Sea; Porto Garibaldi (biogenic), Meride/Riva di Solto (thermal), and Marnoso Arenacea (thermal)

    USGS Publications Warehouse

    Lindquist, Sandra J.

    1999-01-01

    The Porto Garibaldi total petroleum system dominates the Po Basin Province of onshore northern Italy and offshore Italy and Croatia in the northern Adriatic Sea. Porto Garibaldi contains Pliocene (primarily) and Pleistocene (secondarily) biogenic gas ? approximately 16 TCF (2.66 BBOE) ultimately recoverable ? accumulated in co-eval siliciclastic reservoirs. This area was the northwestern edge of the Gondwanan (African) continental plate in pre-Hercynian time until the assembly of Pangea, a dominantly carbonate passive continental margin during the Mesozoic breakup of Pangea, and a Cenozoic collision zone with siliciclastic foredeep and foreland regions surrounded by thrust belts. At least two other petroleum systems, with Triassic (Meride / Riva di Solto) and Miocene (Marnoso Arenacea) source rocks, contribute oil and thermal gas reserves (nearly 1 BBOE) to the province. The major time of hydrocarbon expulsion of the thermal systems was Late Neogene during the Alpine and Apennine orogenies. Local Mesozoic oil expulsion from Triassic rocks also occurred, but those oils either were not trapped or were leaked from faulty traps through time.

  9. Experimental development of a new protocol for extraction and characterization of microplastics in fish tissues: First observations in commercial species from Adriatic Sea.

    PubMed

    Avio, Carlo Giacomo; Gorbi, Stefania; Regoli, Francesco

    2015-10-01

    The presence of microplastics in the marine environment has raised scientific interest during the last decade. Several organisms can ingest microplastics with potentially adverse effects on the digestive tract, respiratory system and locomotory appendages. However, a clear evidence of tissue accumulation and transfer of such microparticles in wild organisms is still lacking, partially hampered by technical difficulties in isolation and characterization protocols from biological samples. In this work, we compared the efficacy of some existing approaches and we optimized a new protocol allowing an extraction yield of microplastics from fish tissues ranging between 78% and 98%, depending on the polymer size. FT-IR analyses confirmed that the extraction procedure did not affect the particles characteristics. The method was further validated on the fish mullet, Mugil cephalus, exposed under laboratory conditions to polystyrene and polyethylene; the particles were isolated and quantified in stomach and liver, and their presence in the hepatic tissue was confirmed also by histological analyses. A preliminary characterization revealed the presence and distribution of microplastics in various fish species collected along the Adriatic Sea. FT-IR analyses indicated polyethylene as the predominant polymer (65%) in the stomach of fish. The overall results confirmed the newly developed method as a reliable approach to detect and quantify microplastics in the marine biota. PMID:26210759

  10. Surface drift prediction in the Adriatic Sea using hyper-ensemble statistics on atmospheric, ocean and wave models: Uncertainties and probability distribution areas

    USGS Publications Warehouse

    Rixen, M.; Ferreira-Coelho, E.; Signell, R.

    2008-01-01

    Despite numerous and regular improvements in underlying models, surface drift prediction in the ocean remains a challenging task because of our yet limited understanding of all processes involved. Hence, deterministic approaches to the problem are often limited by empirical assumptions on underlying physics. Multi-model hyper-ensemble forecasts, which exploit the power of an optimal local combination of available information including ocean, atmospheric and wave models, may show superior forecasting skills when compared to individual models because they allow for local correction and/or bias removal. In this work, we explore in greater detail the potential and limitations of the hyper-ensemble method in the Adriatic Sea, using a comprehensive surface drifter database. The performance of the hyper-ensembles and the individual models are discussed by analyzing associated uncertainties and probability distribution maps. Results suggest that the stochastic method may reduce position errors significantly for 12 to 72??h forecasts and hence compete with pure deterministic approaches. ?? 2007 NATO Undersea Research Centre (NURC).

  11. Benthic community and biological trait composition in respect to artificial coastal defence structures: a study case in the northern Adriatic Sea.

    PubMed

    Munari, Cristina

    2013-09-01

    Biological Traits Analysis (BTA) is a method for addressing ecological functioning based on traits exhibited by members of biological assemblages. This study explores and compares species and biological trait patterns on either side (landward and seaward) of coastal breakwater structures in northwestern Adriatic Sea (Italy), with the aim of giving insights and knowledge for management of sandy beach systems affected by coastal development. Eight ecological traits of 96 benthic species were considered. Taxon composition evidenced differences in benthic assemblages across time and exposure: landward and seaward communities shared less than 50% of the total number of species. BTA suggested a no-management effect in the functioning of benthic assemblages. Dominant traits modalities were deposit-feeding, short life, small body size, short life span, iteroparity, gonocorism, with plankto-planktotrophic larvae. The results of BTA highlighted similarities and stability in trait composition contrary to species composition, suggesting a possible persistence in benthic functioning despite the occurrence of species replacements. To best of my knowledge, this study is one of the first attempts to investigate the effects of a management measure (submerged shore-parallel barriers with groynes) in a shallow marine system by means of BTA. PMID:23806856

  12. Seamount physiography and biology in North-East Atlantic and Mediterranean Sea

    NASA Astrophysics Data System (ADS)

    Morato, T.; Kvile, K. Ø.; Taranto, G. H.; Tempera, F.; Narayanaswamy, B. E.; Hebbeln, D.; Menezes, G.; Wienberg, C.; Santos, R. S.; Pitcher, T. J.

    2012-12-01

    This work aims at characterising the seamount physiography and biology in the OSPAR Convention limits (North-East Atlantic Ocean) and Mediterranean Sea. We first inferred potential abundance, location and morphological characteristics of seamounts, and secondly, summarized the existing biological, geological and oceanographic in-situ research, identifying examples of well-studied seamounts. Our study showed that the seamount population in the OSPAR area (North-East Atlantic) and in Mediterranean Sea is large with around 1061 and 202 seamount-like features, respectively. Similarly, seamounts occupy large areas of about 1 116 000 km2 in the OSPAR region and of about 184 000 km2 in the Mediterranean Sea, which is much larger than previously thought. The presence of seamounts in the North-East Atlantic has been known since the late 19th Century but overall knowledge regarding seamount ecology and geology is still relatively poor. Only 37 seamounts in the OSPAR area (3.5% of all seamounts in the region), 22 in the Mediterranean Sea (9.2% of all seamounts in the region) and 25 in the North-East Atlantic south of the OSPAR have in-situ information. Seamounts mapped in both areas are in general very heterogeneous, showing diverse geophysical characteristics. These differences will likely affect the biological diversity and production of resident and associated organisms.

  13. Mediterranean and Black Sea organisms and algae from mariculture as sources of antitumor drugs.

    PubMed

    Apryshko, Galina N; Ivanov, Valeriy N; Milchakova, Natalya A; Nekhoroshev, Mikhail V

    2005-06-01

    Mussels and tunicates cultivated in Mediterranean and Black Sea are the sources of antitumor drugs. Three compounds isolated from these animals (ET-743, aplidin and bryostatin-1) are on the II-III stages of clinical trials. Carotenoid fucoxantin that is present in edible brown algae possesses antitumor activity. The consumption of brown macrophyts decreases the risk of cancer development. PMID:15995624

  14. Composition and sources of sedimentary organic matter in the deep Eastern Mediterranean Sea

    NASA Astrophysics Data System (ADS)

    Pedrosa-Pàmies, R.; Parinos, C.; Sanchez-Vidal, A.; Gogou, A.; Calafat, A.; Canals, M.; Bouloubassi, I.; Lampadariou, N.

    2015-07-01

    Surface sediments collected from deep slopes and basins (1018-4087 m depth) of the oligotrophic Eastern Mediterranean Sea have been analysed for bulk elemental and isotopic composition of organic carbon, total nitrogen and selected lipid biomarkers, jointly with grain size distribution and other geochemical proxies. The distribution and sources of sedimentary organic matter (OM) have been subsequently assessed and general environmental variables, such as water depth and currents, have been examined as causative factors of deep-sea sediment characteristics. Lithogenic and biogenic carbonates are the dominant sedimentary fractions, while both bulk and molecular organic tracers reflect a mixed contribution from autochthonous and allochthonous sources for the sedimentary OM, as indicated by relatively degraded marine OM, terrestrial plant waxes and anthropogenic OM including degraded petroleum by-products, respectively. Wide regional variations have been observed amongst the studied proxies, which reflect the multiple factors controlling sedimentation in the deep Eastern Mediterranean Sea. Our findings highlight the role of deep Eastern Mediterranean basins as depocentres of organic-rich fine-grained sediments (mean 5.4 ± 2.4 μm), with OM accumulation and burial due to aggregation mechanisms and hydrodynamic sorting. A multi-proxy approach is hired to investigate the biogeochemical composition of sediment samples, which sheds new light on the sources and transport mechanisms along with the impact of preservation vs. diagenetic processes on the composition of sedimentary OM in the deep basins of the oligotrophic Eastern Mediterranean Sea.

  15. Dominant molluscan taxa in the northern Adriatic Sea over the last centuries: down-core changes in shell communities and their implications for an ecological history

    NASA Astrophysics Data System (ADS)

    Haselmair, Alexandra; Gallmetzer, Ivo; Tomasovych, Adam; Stachowitsch, Michael; Zuschin, Martin

    2015-04-01

    The northern Adriatic Sea, with its densely populated shoreline, is among the most degraded marine ecosystems worldwide and therefore particularly suited to study ecosystem modification under human pressure. In particular, the period of the last 500 to 1500 years witnessed major anthropogenic impacts here. The present study reconstructs major ecological shifts over this timespan by identifying down-core changes in molluscan death assemblages that can serve as proxies for changing environmental conditions. Here, we focus on taxonomical down-core fluctuations and changes in abundance of key bivalve and gastropod taxa found at seven sampling stations spread throughout the northern Adriatic basin. At these stations, which were chosen in order to cover different sediment types, nutrient conditions and degrees of exploitation, several cores of 1.5 m length and diameters of 90 and 160 mm were taken and sliced into smaller subsamples of 2 and 5 cm, respectively. The samples were sieved through a 1 mm mesh size and all the shells found counted and identified to species level if possible. In total, 114 bivalve and 112 gastropod species were recorded. At the Po delta and Panzano bay stations, characterized by muddy sediments, Corbula gibba and Kurtiella bidentata were the dominant bivalve species, Nassarius pygmaeus and Turritella communis the most abundand gastropods. In the sandy mud from the Brijuni islands, the bivalves Timoclea ovata and Striarca lactea were very numerous, whereas at the Piran station, characterized by a similar sediment composition, Gouldia minima and Corbula gibba reached the highest numbers. Overall abundances of bivalve and gastropod species differed markedly between stations. In all cores, the incidence of individual species varied down-core. Opposite trends were recorded for Brijuni and Piran station: at Piran, the abundance peaked in the uppermost sediment layers while at the Brijuni islands the number of most gastropod and bivalve species

  16. Total assemblages of benthic foraminifera from a mixed siliciclastic/carbonate inner shelf; preliminary results from the bays of Soline and Nin (Adriatic Sea, Croatia)

    NASA Astrophysics Data System (ADS)

    Vidović, J.; Ćosović, V.; Juračić, M.; Benac, Č.

    2012-04-01

    Eastern Adriatic shelf is mixed siliciclastic/carbonate area with a great proportion of carbonate biogenous production. This study presents analysis and comparison of total benthic foraminiferal assemblages (their composition, diversity and distribution) in surface sediments from two Eastern Adriatic shallow water bays (Soline and Nin Bay), sampled seasonally from 2006 to 2008. In order to characterize the carbonate sediment production, 62 samples along the bathymetric profiles (from 2 to 20 m) were collected by scuba diving with short PVC corers. Granulometrical analysis was done using method of wet sieving. Statistical analyses (cluster analysis, PCA) were performed using Past program. The most abundant biogenous components in different sediments from Soline Bay (muddy sandy gravel and mud) are foraminifera, followed by fragments of mollusks, gastropods, bryozoans and sea urchins. Foraminiferal assemblages are high diversified as confirmed by Shannon-Wiener index varying from 2.14 to 3.39, Fisher α index from 5.74 to 16.30 and Equitability from 0.32 to 0.72. The shallowest part of the bay is covered with the sand, consisted of high proportion of siliciclastic component and impoverished in biogenous remnants. Foraminiferal assemblages have low diversity (Shannon-Wiener index 1.36, Fisher α index 2.31 and Equitability 0.32). Throughout Nin Bay, sediments (classified as sand, muddy sand and mud) are consisted of various biogenic remnants. Foraminiferal assemblages have high biodiversity, with Shannon-Wiener index varying from 2.51 to 3.20, α-Fisher index from 7.84 to 12.64 and Equitability from 0.37 to 0.77. Statistical analyses (cluster analysis and PCA) grouped foraminifera in two major assemblages, related to sediment type. On sandy and gravely substrates, assemblage is dominated by epifaunal genera and species: Quinqueloculina sp. (6-20%), Elphidium sp. (5-16%), Neoconorbina terquemi (6-10 %) and Asterigerinata mamilla (5-7%). Infaunal species, Ammonia

  17. Regional Risk Assessment for the analysis of the risks related to storm surge extreme events in th